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Bulletin of the Global Volcanism Network Volume 34, Number 12, December 2009
From: "Ed Venzke" <VENZKEE@xxxxxx>
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Bulletin of the Global Volcanism Network Volume 34, Number 12, December 2009
From: "Ed Venzke" <VENZKEE@xxxxxx>
****************************************************************
Bulletin of the Global Volcanism Network
Volume 34, Number 12, December 2009
Volume 34, Number 12, December 2009
Mayon (Philippines) December 2009 eruption causes evacuation of more than 47,000 people
Kerinci (Indonesia) Eruptions, ash plumes, and seismicity during 1-21 April 2009
Sangean Api (Indonesia) Explosive eruptions during 1997-1999 were previously unreported
Gaua (Vanuatu) Significant ashfall through early January 2010
West Mata (Tonga) Deep submarine volcano found to be composed of boninite
Galeras (Colombia) Explosive eruptions in September and November 2009, January 2010
Pacaya (Guatemala) Variable activity in 2009 and early 2010
Fuego (Guatemala) Many small ash plumes and some lava flows during 2008-2009; instrumented study
Cleveland (USA) At least three eruptions during 2009, with a possible fourth on 12 December
Kerinci (Indonesia) Eruptions, ash plumes, and seismicity during 1-21 April 2009
Sangean Api (Indonesia) Explosive eruptions during 1997-1999 were previously unreported
Gaua (Vanuatu) Significant ashfall through early January 2010
West Mata (Tonga) Deep submarine volcano found to be composed of boninite
Galeras (Colombia) Explosive eruptions in September and November 2009, January 2010
Pacaya (Guatemala) Variable activity in 2009 and early 2010
Fuego (Guatemala) Many small ash plumes and some lava flows during 2008-2009; instrumented study
Cleveland (USA) At least three eruptions during 2009, with a possible fourth on 12 December
Mayon
Luzon, Philippines
13.257°N, 123.685°E; summit elev. 2,462 m
All times are local (= UTC + 8 hours)
Luzon, Philippines
13.257°N, 123.685°E; summit elev. 2,462 m
All times are local (= UTC + 8 hours)
After erupting in September and November 2009 (BGVN 34:10), monitoring of Mayon by the Philippine Institute of Volcanology and Seismology (PHIVOLCS) continued. Renewed eruptions began on 14 December 2009 with ash columns reaching as high as 1,000 m above the summit, incandescent materials rolling downslope from the crater, and a lava flow descending SE from the summit (table 1). More than 47,000 people were ordered to evacuate for nearly three weeks (figure 1), requiring them to abandon homes and farms (figure 2). International news attention was acute, highlighting evacuations, the volcano's grandeur, and glow over substantial areas in long-exposure night photos.
Table 1. Daily summaries of observations reported at Mayon, including seismicity, SO2 emission rates, and other observations (including Alert Levels) during 14 December 2009-12 January 2010. Numbers of events represent counts from the seismic monitoring network over a 24-hour period prior to the stated reporting date/time (except as noted). Rockfall events are related to the detatchment of fresh lava fragments at the volcano's upper slopes. Ash explosions and other observation are based on actual sightings. SO2 emission rates, measured by FLYSPEC, are for the day before the reporting date. Courtesy of PHIVOLCS.
Report Date(local time) Volcanic earthquakes Ash SO2 flux
and rockfalls explosions (t/d)
Observations
and rockfalls explosions (t/d)
Observations
14 Dec 09 (2000) VE: 23(0800-1600) 6 535
(3 minutes at 0704)
Ash columns (gray to brown) to 1 km above summit, drifting WSW and WNW; incandescent
materials rolling downslope ~3 km towards Bonga, Buyuan, Mabinit channels. Alert Level
raised to 3.
15 Dec 09 (0800) VE: 83 -- 757
Incandescent lava fragments from summit crater rolling downslope ~3 km.
Incandescent lava fragments from summit crater rolling downslope ~3 km.
16 Dec 09 (0800) VE: 78 -- 750
Lava front (~700-800 m from summit) and incandescent fragments ~3-4 km along Bonga gully.
Lava front (~700-800 m from summit) and incandescent fragments ~3-4 km along Bonga gully.
18 Dec 09 (0700) VE: 248 7 1,065
Dark gray to dark brown ash columns up to 1 km above summit, drifting SW; crater glow.
Dark gray to dark brown ash columns up to 1 km above summit, drifting SW; crater glow.
19 Dec 09 (0700) VE: 197 15 2,034
18 volcanic earthquakes; white to grayish ash columns up to 2 km above summit, drifting
SW; steam dirty white to light brown; crater glow, continuous rolling downslope of
incandescent materials from crater.
18 volcanic earthquakes; white to grayish ash columns up to 2 km above summit, drifting
SW; steam dirty white to light brown; crater glow, continuous rolling downslope of
incandescent materials from crater.
20 Dec 09 (0700) VE: 222 -- 7,024
Dirty white to gray ash columns to 500 m above summit, drifting SW; crater glow,
continuous rolling downslope of incandescent materials; lava flow ~ 4.5 km along
Bonga-Buyuan gully; Alert Level raised to 4.
Dirty white to gray ash columns to 500 m above summit, drifting SW; crater glow,
continuous rolling downslope of incandescent materials; lava flow ~ 4.5 km along
Bonga-Buyuan gully; Alert Level raised to 4.
21 Dec 09 (0700) VE: 1,942 many 6,089
Intensified crater glow and rolling incandescent fragments from crater; lava flows along
Bonga-Buyuan (to ~5 km from crater), Miisi, Lidong gullies; lava fountains rose ~200 m.
Intensified crater glow and rolling incandescent fragments from crater; lava flows along
Bonga-Buyuan (to ~5 km from crater), Miisi, Lidong gullies; lava fountains rose ~200 m.
22 Dec 09 (0700) VE: 1,266 reported 6,529
Lava flows along Bonga-Buyuan (to ~5 km from crater), Miisi, Lidong gullies.
Lava flows along Bonga-Buyuan (to ~5 km from crater), Miisi, Lidong gullies.
23 Dec 09 (0700) VE: 1,051 66 6,737
Ash columns (gray to light brown) to 1 km above summit, drifting SW; lava continuously
flowed along Bonga-Buyuan, Miisi, Lidong gullies.
Ash columns (gray to light brown) to 1 km above summit, drifting SW; lava continuously
flowed along Bonga-Buyuan, Miisi, Lidong gullies.
24 Dec 09 (0700) VE: 815 21 5,737
Ash columns to 1.5 km above summit; lava fountains reached 500 m; lava continuously
flowed along Bonga-Buyuan, Miisi, Lidong gullies.
Ash columns to 1.5 km above summit; lava fountains reached 500 m; lava continuously
flowed along Bonga-Buyuan, Miisi, Lidong gullies.
25 Dec 09 (0700) VE: 871 RF: 98 96 2,738
Ash columns (gray to light brown) up to 2 km above summit; three rockfall events
generated pyroclastic flows that moved down ~2 km from crater.
Ash columns (gray to light brown) up to 2 km above summit; three rockfall events
generated pyroclastic flows that moved down ~2 km from crater.
26 Dec 09 (0700) VE: 406 RF: 142 33 8,993
Ash columns (dirty white to brownish) up to 1 km; lava and rolling incandescent fragments
along Bonga-Buyuan, Miisi, Lidong gullies.
Ash columns (dirty white to brownish) up to 1 km; lava and rolling incandescent fragments
along Bonga-Buyuan, Miisi, Lidong gullies.
27 Dec 09 (0700) VE: 44 RF: 297 9 2,304
Ash columns (dirty white to brown) with lava fragments up to 800-1,000 m above summit;
flowing lava and rolling incandescent lava fragments; edifice remained inflated.
Ash columns (dirty white to brown) with lava fragments up to 800-1,000 m above summit;
flowing lava and rolling incandescent lava fragments; edifice remained inflated.
28 Dec 09 (0700) VE: 44 RF: 137 7 4,329
Ash columns (dirty white to light gray) with lava fragments up to 2 km, drifting SW; lava
flows along Bonga-Buyuan, Miisi, Lidong gullies; rolling incandescent fragments.
Ash columns (dirty white to light gray) with lava fragments up to 2 km, drifting SW; lava
flows along Bonga-Buyuan, Miisi, Lidong gullies; rolling incandescent fragments.
29 Dec 09 (0700) VE: 38 RF: 171 9 3,416
Ash columns (dirty white to brown) to 2 km, drifting W and SW; lava flowed along
Bonga-Buyuan (to 5.8 km), Miisi, Lidong gullies; rolling incandescent fragments.
Ash columns (dirty white to brown) to 2 km, drifting W and SW; lava flowed along
Bonga-Buyuan (to 5.8 km), Miisi, Lidong gullies; rolling incandescent fragments.
30 Dec 09 (0700) VE: 16 RF: 150 1 4,397
Dirty white ash column ~100 m, drifted NW; lava flowed along Bonga-Buyuan (to 5.9 km from
summit), Miisi, Lidong gullies; volcanic edifice remained inflated in NE sector.
Dirty white ash column ~100 m, drifted NW; lava flowed along Bonga-Buyuan (to 5.9 km from
summit), Miisi, Lidong gullies; volcanic edifice remained inflated in NE sector.
31 Dec 09 (0800) VE: 60 RF: 267 -- 1,158
Lava extrusion and rolling incandescent fragments along Bongo gully; white steam drifted
WSW; volcanic edifice remained inflated in NE sector.
Lava extrusion and rolling incandescent fragments along Bongo gully; white steam drifted
WSW; volcanic edifice remained inflated in NE sector.
01 Jan 10 (0700) VE: 28 RF: 91 0 1,255
White steam drifted WSW; flowing lava and rolling incandescent lava fragments.
White steam drifted WSW; flowing lava and rolling incandescent lava fragments.
02 Jan 10 (0800) VE: 13 RF: 68 -- 2,621
White steam; Alert Level lowered to 3.
White steam; Alert Level lowered to 3.
03 Jan 10 (0700) VE: 9 RF: 30 -- 2,094
04 Jan 10 (0700) VE: 7 RF: 33 -- --
05 Jan 10 (0700) VE: 3 RF: 21 -- --
06 Jan 10 (0700) VE: 4 RF: 21 -- 1,914
White steam; pale glow from crater at night.
White steam; pale glow from crater at night.
07 Jan 10 (0700) VE: 20 RF: 20 -- 672
White steam from summit crater.
White steam from summit crater.
08 Jan 10 (0700) VE: 5 RF: 29 -- 1,077
09 Jan 10 (0700) VE: 5 RF: 20 -- 1,345
Glow from crater at night.
Glow from crater at night.
10 Jan 10 (0700) VE: 8 RF: 12 -- 759
White steam from summit crater; pale glow from crater at night.
White steam from summit crater; pale glow from crater at night.
11 Jan 10 (0700) VE: 4 RF: 18 -- --
White steam from summit crater, reaching 300-500 m above crater rim, drifting WSW; pale
glow from crater at night.
White steam from summit crater, reaching 300-500 m above crater rim, drifting WSW; pale
glow from crater at night.
12 Jan 10 (0700) VE: 6 RF: 17 -- 820
White steam from summit crater; pale glow from crater at night; ground deformation at
Buang and Lidong level lines showed deflation compared to 2 December 2009 survey.
White steam from summit crater; pale glow from crater at night; ground deformation at
Buang and Lidong level lines showed deflation compared to 2 December 2009 survey.
Figure 1. A Mayon map variously showing volcanic hazard (3-, 6-, and 8-km radius danger zones), evacuation centers, Albay Province census data (shaded areas defined on legend), and the actual evacuated population (44,637 people). The locations evacuated (table at upper left) were within the 6-km Permanent Danger Zone and SE Quadrant High-Risk Zone (7-8 km radial distance) and came from eight municipalities and their 32 subdivisions (barangays). The table shows both the targeted number of evacuees and the actual number as of 1100 on 21 December. Courtesy of the United Nations OCHA, 21 December 2009.
Figure 2. A farmer tills the soil while Mayon steams in the background. Many residents in threatened areas were reluctant to leave their homes and livestock. Date and photographer unknown. Courtesy of AFP.
At the onset of the eruption, after a minor ash explosion at 0740 on 14 December, five more minor ash explosions occurred at the summit crater. These explosions produced brownish to grayish ash clouds which were blown by strong winds WSW and WNW. The explosions lasted for ~ 3 minutes and were registered on the seismograph as explosion earthquakes. Twenty-three volcanic earthquakes were also recorded from 0800 to 1600. During the morning of 14 December the sulfur dioxide (SO2) emission rate measured by FLYSPEC [a miniature, light-weight ultraviolet correlation spectrophotometer (Horton and others, 2006)] was 757 metric tons/day (t/d). At 1800, incandescent materials originating from the summit crater were seen rolling downslope SE ~ 3 km in the direction of Bonga, Buyuan, and Mabinit channels.
On 14 December 2009 PHIVOLCS raised the hazard status to Alert Level 3 (meaning that magma is close to the crater and a hazardous explosive eruption is possible). The alert was again raised, to Level 4 (meaning a hazardous explosive eruption is possible within days), on 20 December. After decreased activity the Alert was lowered to Level 3 on 2 January 2010.
Satellite observations and measurements. Figure 3 shows a satellite image of Mayon captured on 15 December 2009. NASA's Jesse Allen noted that "A small plume of ash and steam is blowing west from the summit. Dark-colored lava or debris flows from previous eruptions streak the flanks of the mountain. A ravine on the southeast slope is occupied by a particularly prominent lava or debris flow."
Figure 3. A natural-color image of Mayon taken 15 December 2009 (N to the top; for approximate scale, the distance from the summit to the coast is ~ 10 km). Image acquired by the Advanced Land Imager on NASA's Earth Observing-1 (EO-1) satellite. Courtesy of NASA.
MODIS/MODVOLC satellite thermal alerts were measured nearly daily during 14-31 December 2009; alerts were absent after 31 December 2009 and at least as late as 12 January 2010. It is noted that during 3 passes of the MODIS satellite (on 24 December at 1715 UTC, 25 December at 1330 UTC, and 28 December at 1400 UTC), 11-pixel alerts occurred each pass that gave some idea of the area covered by the thermal anomaly. Prior to this period, alerts were measured only during an eruption of Mayon from 15 July-25 September 2006 (BGVN 31:07, 31:08, 32:05, and 34:02).
Evacuation. The alert status rose from Level 3 to 4 (on a scale of 1-5) on 20 December (table 1). According to a news article by Sophia Dedace at GMANews.TV on 14 January 2010, between 14 December and 2 January, the threatening eruption prompted the provincial government to evacuate more than 47,000 residents located within Mayon danger zones.
Geologic Summary. Beautifully symmetrical Mayon volcano, which rises to 2,462 m above the Albay Gulf, is the Philippine's most active volcano. The structurally simple volcano has steep upper slopes averaging 35-40° that are capped by a small summit crater. The historical eruptions of this basaltic-andesitic volcano date back to 1616 and range from strombolian to basaltic plinian, with cyclical activity beginning with basaltic eruptions, followed by longer term andesitic lava flows. Eruptions occur predominately from the central conduit and have also produced lava flows that travel far down the flanks. Pyroclastic flows and mudflows have commonly swept down many of the approximately 40 ravines that radiate from the summit and have often devastated populated lowland areas. Mayon's most violent eruption, in 1814, killed more than 1,200 people and devastated several towns.
Reference: Horton, K.A., Williams-Jones, G., Garbeil, H., Elias, T., Sutton, A.J., Mouginis-Mark, P., Porter, J.N., and Clegg, S., 2006, Real-time measurement of volcanic SO2 emissions: validation of a new UV correlation spectrometer (FLYSPEC): Bull. Volc., v. 68, no. 4, p. 323-327 (doi:10.1007/s00445-005-0014-9).
Information Contacts: Philippine Institute of Volcanology and Seismology (PHIVOLCS), Department of Science and Technology, University of the Philippines Campus, Diliman, Quezon City, Philippines (URL: http://www.phivolcs.dost.gov.ph/); Philippine Daily Inquirer, (URL: http://www.inquirer.net/); Vox Bikol (URL: http://www.voxbikol.com/); and Philippine Information Agency, (URL: www.PIA.gov.ph); and GMANews.TV, 6/F GMA Network Center, EDSA corner Timog Avenue, Diliman, Quezon City, 1101, PHILIPPINES (URL: http://www.gmanews.tv/index.html); Jesse Allen, NASA (URL: http://www.nasa.gov), and MODIS/MODVOLC Thermal Alerts, Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://hotspot.higp.hawaii.edu/); Agence France Presse (URL: http://www.afp.com/).
Kerinci
Sumatra, Indonesia
1.697°S, 101.264°E; summit elev. 3,800 m
Sumatra, Indonesia
1.697°S, 101.264°E; summit elev. 3,800 m
Since a 2004 eruption, Kerinci had been relatively quiet except for ash plumes in September 2007 and ash and steam plumes in February, March, and May 2008 (BGVN 33:05). Eruptions sent ash plumes hundreds of meters above the crater during the first three weeks of April 2009, causing ashfall 8 km away. A report on this period by the Center of Volcanology and Geological Hazard Mitigation (CVGHM) noted that the active crater normally emits whitish plumes ~ 300 m above the peak. During September 2007 through at least 21 April 2009 the Alert Level remained at 2 (on a scale of 1-4). Residents and visitors have been advised to remain at least 1 km from the summit and to don masks in cases of heavy ashfall.
According to CVGHM, seismicity also increased at Kerinci during the first three weeks of April 2009. The signals were generally dominated by those from eruptions and their associated seismically detected signals traveling through air (as opposed to rock), 'air blasts.' The daily average of air blasts was 38, with the daily maximum reaching 54. The amplitudes of eruptive earthquake signals were 5-49 mm; the amplitudes of the air blasts were 0.5-9 mm. In addition, earthquakes during this 3-week period also included those of deep volcanic origin on 9 and 10 April (1 per day).
The increased seismicity was accompanied by steam-, ash-, or cinder-bearing plumes, sometimes dense, that rose as high as 500-600 m above the crater. On 3 April an eruption reached ~ 500 m above the crater; variable plumes continued through 12 April. A nearby observation post reported the rumbling of eruptions and ashfall during 19-20 April that extended as much as 8 km from the crater.
The eruptions deposited loose material (ash, cinders, lapilli, volcanic bombs, etc.) along the volcano's slope that leads to a nearby river. CVGHM was concerned that a heavy rain in the vicinity of the volcano could pick up this loose material and cause a lahar along the river channel.
Satellite thermal monitoring using MODVOLC during 2009 recorded over 25 alerts at Kerinci between 29 April and 19 June 2009.
Geologic Summary. The 3,800-m-high Gunung Kerinci in Central Sumatra forms Indonesia's highest volcano and is one of the most active in Sumatra. Kerinci is capped by an unvegetated young summit cone that was constructed NE of an older crater remnant. The volcano contains a deep 600-m-wide summit crater often partially filled by a small crater lake that lies on the NE crater floor, opposite the summit on the SW-rim. The massive, 13 x 25 km wide volcano towers 2,400-3,300 m above surrounding plains and is elongated in a N-S direction. The frequently active Gunung Kerinci has been the source of numerous moderate explosive eruptions since its first recorded eruption in 1838.
Information Contacts: Center of Volcanology and Geological Hazard Mitigation (CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (Email: dali@xxxxxxxxxxxxxx; URL: http://www.vsi.esdm.go.id/); MODVOLC, Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://hotspot.higp.hawaii.edu/).
Sangeang Api
Lesser Sunda Islands, Indonesia
8.20°S, 119.07°E; summit elev. 1,949 m
Lesser Sunda Islands, Indonesia
8.20°S, 119.07°E; summit elev. 1,949 m
A recent translation of an older report from the Center of Volcanology and Geological Hazard Mitigation (CVGHM) discussed previously undocumented interval of eruptions at Sangeang Api (figure 4) during 1997-1999. These eruptions were described, along with other known eruptions, in broad terms in their report. They were generally explosive, with lava domes and lava discharges, similar to the eruptions of 1911, 1953, 1954, 1985-1988.
Figure 4. A photograph of the 13-km-wide Sangeang Api taken on 15 October 2002 by Space Shuttle astronauts (photo STS-112-E-5628). A wide channel running W from provides a path for inferred lava and pyroclastic flows. Courtesy of NASA Earth Observatory.
Dali Ahmad confirmed the occurrence of explosive activity during the 1997-1999 period. These took place without causing casualties because, since 1989, all of the island residents had departed to the nearby Sumbawa Island. No additional eruptions were indicated through at least 2009. In recent times the island's summit crater has produced intermittent steam clouds.
Turner and others (2003) used Uranium-series isotopes to provide insights into Sangeang Api magma evolution. The volcano erupts potassic lavas (SiO2 ~ 47-55%) with a spectrum of xenoliths that record the liquid line of descent. The scientists estimated that the Sangeang Api magma chamber was about 6-10 km^3 in volume and underwent cooling rates of ~ 0.05°C/year.
Geologic Summary. Sangeang Api volcano, one of the most active in the Lesser Sunda Islands, forms a small 13-km-wide island off the NE coast of Sumbawa Island. Two large trachybasaltic-to-tranchyandesitic volcanic cones, 1,949-m-high Doro Api and 1,795-m-high Doro Mantoi, were constructed in the center and on the eastern rim, respectively, of an older, largely obscured caldera. Flank vents occur on the south side of Doro Mantoi and near the northern coast. Intermittent historical eruptions have been recorded since 1512, most of them during in the 20th century.
Reference: Turner, S., Foden, J., George, R., Evans, P., Varne, R., Elburg, M., and Jenner, G., 2003, Rates and processes of potassic magma evolution beneath Sangeang Api volcano, East Sunda Arc, Indonesia: Journal of Petrology, v. 44, no. 3, pp. 491-515.
Information Contacts: Dali Ahmad, Center of Volcanology and Geological Hazard Mitigation (CVGHM), Jalan Diponegoro 57, Bandung 40122, Indonesia (Email: dali@xxxxxxxxxxxxxx; URL: http://www.vsi.esdm.go.id/); NASA Earth Observatory (URL: http://earthobservatory.nasa.gov/).
Gaua
Vanuatu, SW Pacific
14.27°S, 167.50°E; summit elev. 797 m
All times are local (= UTC +11 hours)
Vanuatu, SW Pacific
14.27°S, 167.50°E; summit elev. 797 m
All times are local (= UTC +11 hours)
Beginning on 29 September 2009, Gaua produced a series of eruptions from Mount Garat, a cone in the SW portion of its caldera. The eruptions generated a small pyroclastic flow, thick ash plumes, and elevated sulfur dioxide (SO2) levels. Our last report (BGVN 34:10) described these events through November 2009. This new report carries events into February 2010, and discusses ongoing eruptions and stress on residents. We also present a December 2009 hazard map created by the Vanuatu Department of Geology, Mines and Water Resources (DGMWR) and the New Zealand GNS Science.
A news article on 29 November (Radio New Zealand International) quoted Brad Scott (New Zealand GNS), "Downwind ashfall is falling on the forest, it's falling on the villages, it's falling on the gardens. In some places it's already started to create a desert, in other places it's only light ashfall. But people are suffering from sore eyes, throat inflammation, and [intestinal] problem[s] ...."
The health aspects of the eruption were also noted in the Vanuatu Daily Post on 24 November 2009, stating that the drinking water in the affected area was "contaminated with ash and many of the villagers depend only on spring water by the sea for cooking and drinking. Island cabbages and other greens must be thoroughly washed before they are cooked."
According to the DGMWR and Brad Scott, Gaua continued to erupt in December 2009 and early January 2010, with even stronger explosions than those previously described (BGVN 34:10). According to DGMWR, this eruptive phase was different from previous Gaua eruptions, with denser and darker plumes (figure 5). The Alert Level remained at 2 (on a scale of 0-4).
Figure 5. Photo of an ash plume from Gaua taken on 31 December 2009, viewed from the caldera rim. Courtesy of Vanuatu Department of Geology, Mines and Water Resources (DGMWR).
Ash emissions and ashfall were significant (figure 6). Beginning on 14 December and continuing at least through 8 January 2010, the emission of fine ash from Gaua had been continuous, with ashfall blown W (figure 7). Chemical analysis of the ashfall carried out by York University in England found high concentrations of toxic chemicals. As a result of the ashfall, 257 people were relocated to the upwind side of the island during the last week of November.
Figure 6. Ash from Gaua on 29 December 2009 that fell on plants in Quetekaveau village. Courtesy of DGMWR.
Figure 7. Volcanic hazards map of Gaua illustrating the caldera's topographic margin, the active inner cone (Mount Garet), and Lake Letas, which curves around the N to E to S sides of the caldera floor. The zones 1 (red), 2 (orange), 3 (yellow), and 4 (white or unshaded) are discussed in text. Modified from DGMWR Bulletin Number 4 (14 December 2009).
The 3-km inner circle centered on the active vent (figure 7) represents the area of greatest risk (1, red zone), a region where volcanic projectiles are likely and access is officially banned. A second area of risk lies inside a curve around Mount Garet and surrounding the island's NW side (2, orange zone), a region so delineated because of likely distribution of ongoing plumes by trade winds. This zone is considered exposed to ash and gas; with heavy rains, the water could mix with tephra to create lahars.
A third area of risk (3, yellow zone) trends E-W and forms an elongate region that follows the caldera lake's established drainage along the Lussal valley. Floods and lahars are indicated here. Note the settlements of Lebal (on the E coast directly S of the river mouth) and Siriti (~ 3 km N of Lebal). A sudden eruption could send material into the lake, and the resulting displaced water or water-and-ash mixture would surge down the Lussal river drainage. The villages on the other part of the island (4, white or unshaded) could receive light ashfall, should the wind direction temporarily change.
An 18 January 2010 satellite image (taken by the ozone monitoring instrument) quantifying emissions from Gaua showed the persistence of significant gas flux (figure 8). These emissions became more frequent in December, although the daily SO2 gas flux stayed steady around 3,000 metric tons per day.
Figure 8. OMI satellite data showing SO2 degassing over Ambrym and Gaua volcanoes on 18 January 2010. Courtesy of OMI Sulfur Dioxide Group and DGMWR.
Based on analyses of satellite imagery and pilot observations, the Wellington VAAC reported that at 1300 on 21 January an ash plume rose to an altitude of 3 km and drifted S. They also detected another ash cloud on MODIS satellite imagery on 26 January blowing SE at 3 km altitude.
DGMWR Bulletin Number 7 (dated 29 January 2010) reported that more gas had been emitted since 16 January 2010, followed by multiple explosions with thicker and darker ash plumes. These plumes rose to more than 3 km high and blew towards surrounding villages in the S and W (figures 8 and 9). On 24 January 2010 villagers witnessed strong Strombolian activity.
Figure 9. Ash and gas cloud emission directed to the S part of Gaua Island on 23 January 2009. Courtesy of DGMWR.
The Wellington VAAC reported that on 27 January an ash cloud was seen on satellite imagery. Strong explosions were seen and heard from East Gaua on 29 January. According to the VAAC, the Vanuatu Geohazards Observatory reported that gas-and-ash plumes to altitudes of 3 km altitude that drifted S and W on 29 January and 4 February.
As of 1 February 2010, the hazard status was at Level 2 on the Vanuatu Volcano Alert Level (VVAL) (table 2), but the activity was still increasing. Visitors were advised to avoid approaching the volcano.
Table 2. The hazard status of the crisis on Gaua is addressed with a five-stage scale called the Vanuatu Volcanic Alert Level (VVAL). Courtesy of Vanuatu Geohazards Observatory.
Hazard Description
Level
Level
Level 0 Normal low-level activity
Level 1 Increased activity, danger near crater only
Level 2 Moderate eruptions, danger close to the volcano vent, within parts of Volcanic
Hazards Map Red Zone
Level 3 Large eruption, danger in specific areas within parts of Volcanic Hazards Map
Red and Yellow Zones
Level 4 Very large eruption, island-wide danger (including areas within Red, Yellow and
Green Zones)
Level 1 Increased activity, danger near crater only
Level 2 Moderate eruptions, danger close to the volcano vent, within parts of Volcanic
Hazards Map Red Zone
Level 3 Large eruption, danger in specific areas within parts of Volcanic Hazards Map
Red and Yellow Zones
Level 4 Very large eruption, island-wide danger (including areas within Red, Yellow and
Green Zones)
The MODIS/MODVOLC satellite thermal alerts website showed a 1-pixel alert at 2225 on 21 January 2010, the only alert during the previous year.
Geologic Summary. The roughly 20-km-diameter Gaua Island, also known as Santa Maria, consists of a basaltic-to-andesitic stratovolcano with an 6 x 9 km wide summit caldera. Small parasitic vents near the caldera rim fed Pleistocene lava flows that reached the coast on several sides of the island; several littoral cones were formed where these lava flows reached the sea. Quiet collapse that formed the roughly 700-m-deep caldera was followed by extensive ash eruptions. Construction of the historically active cone of Mount Garat (Gharat) and other small cinder cones in the SW part of the caldera has left a crescent-shaped caldera lake. The symmetrical, flat-topped Mount Garat cone is topped by three pit craters. The onset of eruptive activity from a vent high on the SE flank of Mount Garat in 1962 ended a long period of dormancy.
Information Contacts: E. Garaebiti, S. Todman, C. Haruel, D. Charley, D. Nakedau, J. Cevuard, and A. Worwor, Department of Geology, Mines and Water Resources (DGMWR), Geohazards Unit, Vanuatu (URL: http://www.geohazards.gov.vu/); Brad Scott, Volcano Surveillance, GNS Science, Wairakei Research Centre, Private Bag 2000, Taupo 3352, New Zealand (URL: http://www.gns.cri.nz/); OMI (Ozone Monitoring Instrument) Sulfur Dioxide Group, Joint Center for Earth Systems Technology, University of Maryland Baltimore County (UMBC), 1000 Hilltop Circle, Baltimore, MD 21250, USA (URL: http://so2.umbc.edu/omi/); Vanuatu Daily Post (URL: http://www.dailypost.vu/); Radio New Zealand International (URL: http://www.mzi.com/); Wellington Volcanic Ash Advisory Centre, Meteorological Service of New Zealand Limited, 30 Salamanca Road, Kelburn, PO Box 722, Wellington, New Zealand(URL: http://vaac.metservice.com/vaac/); Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://hotspot.higp.hawaii.edu/).
West Mata
Tonga Islands, SW Pacific
15.10°S, 173.75°W; summit elev. -1,174 m
Tonga Islands, SW Pacific
15.10°S, 173.75°W; summit elev. -1,174 m
The eruption of the submarine back-arc West Mata volcano was reported in May 2009 (BGVN 34:06) at 1,200 m water depth in the NE Lau basin. The activity was discovered during a research cruise aboard the University of Washington's RV Thomas Thompson.
Ken Rubin, a geochemist at the University of Hawaii, reported that during the 2009 cruise a remote operated vehicle (ROV Jason) was used to observe extrusive and mildly explosive (Strombolian, or the deep-submarine equivalent) activity near the summit. Among the many attributes of this event was the unique style of eruption from multiple active vents. In addition, the lavas were composed of boninite (a lava of olivine-bronzite andesite composition containing little or no feldspar), making this the first observed eruption of a lava of this composition. Such lavas have previously been seen only on volcanoes over a million years old, and are thought to represent the early stages of subduction in primitive island arcs. One of the tasks on the cruise was to sample an active lava pillow. Rubin provided several photographs of the sampling sequence, done with a T-handled rod rammed into a molten zone on the pillow (figures 10 and 11). Some of the sample has been distributed for analysis.
Figure 10. Photograph taken from the ROV Jason of a sample of lava from West Mata being placed in a container aboard the vehicle. Courtesy of K. Rubin.
Figure 11. Photograph of lava sample collected at West Mata. Courtesy of K. Rubin.
According to press release 09-243 of 17 December 2009 by the National Science Foundation (NSF), the expedition's chief scientist and a chemical oceanographer at the University of Washington, Joseph Resing, stated that "we found a type of lava never before seen erupting from an active volcano, and for the first time observed molten lava flowing across the deep-ocean floor." Bob Embley, marine geologist at NOAAs' Pacific Marine Environmental Laboratory, noted that "since the water pressure at that depth supresses the violence of the volcano's explosions, we could get an underwater robot within feet of the active eruption." Imagery includes large molten lava bubbles ~ 1 m across bursting into cold seawater, glowing red vents exploding lava particles into the sea, and lava flows. Video images may be seen on a number of websites (such as NSF).
Water from the volcano was very acidic, and Tom Shank, a biologist from the Woods Hole Oceanographic Institution, found that shrimp were the only animals thriving in the vent water near the eruption. The press release from NSF included a video of the volcanic explosions.
Several papers pertaining to research conducted on the 2009 eruption of West Mata were presented at the 2009 American Geophysical Union Fall Meeting, 14-18 December 2009; titles and authors of abstracts are shown in the reference list below.
Geologic Summary. West Mata, a submarine volcano rising to within 1,174 m of the sea surface, is located in the northeastern Lau Basin at the northern end of the Tonga arc, about 200 km SW of Samoa. West Mata volcano lies about 7 km west of another submarine volcano, East Mata; both lie at the northern end of the Tonga arc, north of the historically active Curacoa submarine volcano. The two volcanoes were discovered during a November 2008 NOAA Vents Program expedition, and West Mata was found to be producing submarine hydrothermal plumes consistent with a recent or lava effusion. A return visit in May 2009 documented explosive and effusive activity from two closely spaced vents, one at the summit, and the other on the SW rift zone.
References: Caress, D.W., Thomas, H., Conlin, D., and Clague, D.A., 2009, Fine-scale morphology of West Mata volcano and the Northeast Lau Spreading Center, Lau Basin from AUV multibeam surveys, American Geophysical Union 2009 Fall Meeting abstract V51D-1731.
Clague, D.A., Rubin, K.H., and Keller, N.S., 2009, Products of submarine fountains and bubble-burst eruptive activity at 1200 m on West Mata volcano, Lau Basin, American Geophysical Union 2009 Fall Meeting abstract V43I-02.
Huber, J.A., Cantin, H., Resing, J., and Butterfield, D.A., 2009, Microbial communities in erupting fluids from West Mata volcano, Tonga Arc, American Geophysical Union 2009 Fall Meeting abstract V41I-07.
Keller, N.S., Rubin, K.H., Clague, D.A., Michael, P.J., Resing, J.A., Cooper, L.B., Shaw, A.M., Ono, S., and Tamura, Y., 2009, Sulfur in submarine eruptions: Observations and preliminary data from West Mata, NE Lau Basin, American Geophysical Union 2009 Fall Meeting abstract V43I-08.
Lin, H., Cowen, J.P., Butterfield, D.A., Embley, R.W., and Resing, J., 2009, Dissolved organic carbon distribution in two hydrothermal systems - West Mata, NE Lau Basin during an eruption event and basement fluids from sediment-buried Juan de Fuca Ridge flanks, American Geophysical Union 2009 Fall Meeting abstract B21D-06.
Michael, P.J., Escrig, S., Rubin, K.H., Cooper, L.B., Langmuir, C.H., Clague, D.A., Keller, N.S., and Plank, T., 2009, Major and trace elements and volatiles in glasses from the 2009 Rapid Response Expedition to West Mata volcano and Northeast Lau spreading center (NELSC), American Geophysical Union 2009 Fall Meeting abstract V51D-1720.
Resing, J., Lupton, J., Embley, R., Baker, E., and Lilley, M. (compilers), 2009, Preliminary findings from the North Lau eruption sites, informal report, 2/5/09 (URL: http://www.ridge2000.org/science/downloads/email/Nlaupreliminaryfindings25.pdf).
Information Contacts: Ken Rubin, NOAA, University of Hawaii (Email: krubin@xxxxxxxxxx); National Science Foundation (NSF) (URL: http://www.nsf.gov/news/news_summ.jsp?cntn_id=1160988org+NSF&from+news); American Geophysical Union 2009 Fall Meeting (URL: http://agu-fm09.abstractcentral.com/planner).
Galeras
Colombia
1.22°N, 77.37°W; summit elev. 4,276 m
Colombia
1.22°N, 77.37°W; summit elev. 4,276 m
Our last report on Galeras discussed ongoing explosions and ash plumes during February-June 2009 (BVGN 34:07). That report concluded with a rise in the alert level to II (orange; "probable eruption in terms of days or weeks") on 26 June 2009. That change followed elevated seismicity suggestive of precursory behavior similar to that of previous eruptions. This report continues coverage of activity from July 2009 to January 2010, including eruptions on 30 September and 30 November 2009, and 2 January 2010.
Overflight observations from 12 and 13 July 2009 found reduced crater temperatures, including a decrease from 220 to 100°C in one small area. In a 28 July report, INGEOMINAS reported earthquakes of up to M 1.6. Due to continuing low levels of activity, on 4 August the Alert Level was decreased to III (on a scale of I-IV, with I being high). It was also noted that there were active fumaroles on the W flank. An episode of tremor lasting ~ 3 hours was reported on 10 August, and an overflight on 23 August observed an increase in fumarolic activity since 12 July. On 8 September 2009 INGEOMINAS reported recent earthquakes of up to M 1.5.
Eruption of 30 September 2009. At 0914 on 30 September, INGEOMINAS reported an explosive eruption prompting the rise in Alert Level to I (red; "imminent eruption or in progress"). A second INGEOMINAS report stated that National Park personnel observed two explosions and ejection of incandescent material at the active cone, as well as an ash plume rising to ~ 12 km altitude that drifted E and later N. The SO2 measurements between 0930 and 1000 included values between 1,100 and 9,300 tons/day. Ashfall was reported in Sandona (15 km NW), Ancuya, Linares, La Llanada, and Sotomayor (40 km NW). Seismicity decreased after the eruption and the Alert Level was lowered on 1 October to II and on 6 October to III.
On 30 October, INGEOMINAS reported that degassing had decreased and seismicity had increased, a previous indication of possible eruptions; the Alert Level was raised to II. A 3 November report described decreasing SO2 emissions and seismicity, and INGEOMINAS reported on 10 November that seismicity continued to decrease and SO2 was not detected. An overflight on 14 November detected low rates of gas discharge and thermal anomalies inside the main crater measuring 110°C.
Eruption of 20 November 2009. INGEOMINAS reported an explosive eruption on 20 November at 2037. Five explosions were reported by residents in San Cayetano, and incandescence was observed at the summit. The Washington Volcanic Ash Advisory Center (VAAC) reported an eruptive column to ~ 14 km altitude that drifted N, and ashfall occurred in Narino, La Florida, and Bellavista. INGEOMINAS stated that seismicity levels associated with the eruption were lower than those during the 30 September eruption. Seismicity increased after the eruption but then gradually decreased. The Alert Level had been raised to I during the eruption but was dropped to II on 21 November and to III on 27 November.
Overflights on 26 November and 3 December revealed fumarolic activity in the main crater, with respective estimated temperatures up to 200°C and on the latter date, 155°C. The Alert Level was raised to II.
Earthquakes with magnitudes of up to 2.2 were measured during 12-15 December, at distances of up to 2 km from the crater and at depths of up to 3 km. INGEOMINAS noted that seismicity included both tornillo (BVGN 18:04) and pseudo-tornillo earthquakes. The seismicity was similar to the behavior prior to the eruptions on 30 September and 20 November. In a 29 December report, INGEOMINAS noted that these types of earthquakes have preceded the majority of the explosive eruptions of Galeras from 1992 to 2009.
Eruption of 2 January 2010. An explosive eruption at Galeras on 2 January at 1943 lasted ~ 30 minutes and prompted INGEOMINAS to raise the Alert Level to I. Ash emissions, summit incandescence, and ejected incandescent blocks that ignited surrounding areas of the volcano were observed. The Washington VAAC reported an eruptive column to 12 km altitude that drifted W and NW, with ashfall observed in Sandona, Consaca, Ancuya, Linares, Samaniego, Santacruz-Guachavez and La Llanada. Seismicity declined after the end of the eruptive event and INGEOMINAS lowered the Alert Level to II. An overflight on 3 January revealed diffuse white-colored gas plumes from the main crater. On 5 January ashfall was reported in areas as far as 110 km to the W, with falling blocks having reached distances of 3.2-3.5 km from the crater.
INGEOMINAS reported eight tornillo-type seismic events between 16-18 January, similar to those observed before previous eruptions, followed by low-to-moderate SO2 emissions beginning on 19 January and continuing low through at least 26 January.
Geologic Summary. Galeras, a stratovolcano with a large breached caldera located immediately west of the city of Pasto, is one of Colombia's most frequently active volcanoes. The dominantly andesitic Galeras volcanic complex has been active for more than 1 million years, and two major caldera collapse eruptions took place during the late Pleistocene. Long-term extensive hydrothermal alteration has affected the volcano. This has contributed to large-scale edifice collapse that has occurred on at least three occasions, producing debris avalanches that swept to the west and left a large horseshoe-shaped caldera inside which the modern cone has been constructed. Major explosive eruptions since the mid Holocene have produced widespread tephra deposits and pyroclastic flows that swept all but the southern flanks. A central cone slightly lower than the caldera rim has been the site of numerous small-to-moderate historical eruptions since the time of the Spanish conquistadors.
Information Contacts: Instituto Colombiano de Geologia y Mineria (INGEOMINAS), Observatorio Vulcanologico y Sismologico de Popayan, Popayan, Colombia (Email: uop@xxxxxxxxxxxx).
Pacaya
Guatemala
14.381°N, 90.601°W; summit elev. 2,552 m
All times are local (= UTC - 6 hours)
Guatemala
14.381°N, 90.601°W; summit elev. 2,552 m
All times are local (= UTC - 6 hours)
Our last report on Pacaya was in August 2008 (BGVN 33:08), which covered activity through September 2008. Unless otherwise indicated, the following report is a compilation of reports from Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hydrologia (INSIVUMEH).
During 8-14 October 2008, the pattern of previous activity continued with multiple lava flows on the W and SW flanks of MacKenney cone that traveled a maximum distance of 250 m and continued to fill in the area between the cone and Cerro Chino crater to the N. Avalanches occurred from the lava-flow fronts on 8 October. Fumarolic plumes drifted SW.
Based on analysis of satellite imagery, the Washington VAAC reported that on 2 November 2008 a possible ash-and-gas plume was emitted from Pacaya and drifted E. On 3 November, INSIVUMEH reported that fumarolic plumes drifted S at a low altitude. Ash occasionally entrained by strong winds drifted S. Multiple lava flows on the S and SW flanks of MacKenney cone traveled a maximum distance of 400 m on 3 and 4 November, and continued to fill in the area between the cone and Cerro Chino crater to the N. Fumarolic plumes drifted E on 4 November. On 20 November fumarolic plumes from Pacaya's MacKenney cone drifted S at a low altitude. Ash occasionally entrained by strong winds drifted S. Multiple lava flows on the S, W, and SW flanks of the cone traveled 50-300 m during 20-21 and 25 November.
On 12 December 2008 fumarolic plumes from Pacaya's MacKenney cone drifted NE at a low altitude. Three lava flows, 150, 250, and 800 m long, were observed from the S. Seismic data indicated small explosions at the crater.
On 30 January and 3 February 2009, white and blue fumarolic plumes from MacKenney cone drifted S and SW at a low altitude. One lava flow, 75-100 m long, traveled down the SW flank.
On 12, 16, and 17 March 2009, fumarolic plumes from MacKenney cone drifted S at a low altitude. Lava flows, 25-200 m long, traveled S, SW, and W. Explosions during March ejected greater amounts of material that was deposited in the crater, enlarging the cones there. On 23 March, visual and audible changes in Strombolian activity were noted. Vigorous degassing produced sounds resembled airplane engines.
In a report issued on 3 April 2009, INSIVUMEH stated that Strombolian explosions from MacKenney cone during the previous few days ejected material 25 m into the air. On 2 April, lava flow volume increased, sending four lava flows W and one SW; the flows traveled 25-200 m. The seismic network detected tremor and explosions. On 6 April, lava flows on the W flank traveled 150-300 m, causing lava to collect on the SW flank. Activity from MacKenney cone was continuous; one cone emitted gas and explosions about every 5-10 minutes, and a second cone ejected tephra 25 m high. On 7 April, one lava flow traveled 150 m W and one traveled 200 m SW. INSIVUMEH recommended that CONRED coordinate with authorities in Pacaya National Park to restrict visitors from climbing Pacaya. On 24 and 28 April, INSIVUMEH reported gas emissions from Pacaya's MacKenney cone; occasional ash explosions ejected tephra 15-25 m high. The seismic network detected tremor and explosions. A small spatter cone being built in the S part of the crater was 4 m high. Rumbling noises were heard 3-5 km away and degassing produced sounds resembling airplane engines. Lava flows traveled 50-400 m down the SW flank and fumarolic plumes drifted S. This pattern of activity continued throughout May 2009.
For the remainder of 2009, the pattern remained much the same. On 5, 8, and 9 June 2009, white and blue fumarolic plumes from Pacaya's MacKenney cone rose to as high as 400 m and drifted, S, W and SW. Multiple lava flows up to 600 m long, were emitted from an area on the lower S flank, SW from the main edifice and traveled S, SW and W. Incandescence at night was noted on 20 November and 18 December.
Similar activity continued in 2010. On 8, 11, and 12 January 2010, white and blue fumarolic plumes from Pacaya's MacKenney cone rose up 400 m and drifted S and SW. Multiple lava flows on the S, SW, and W flanks traveled 25-200 m. Incandescence was noted at night from one of the inter-crater cones on 8 January and from MacKenney cone on 11 and 12 January.
Geologic Summary. Eruptions from Pacaya, one of Guatemala's most active volcanoes, are frequently visible from Guatemala City, the nation's capital. Pacaya is a complex basaltic volcano constructed just outside the southern topographic rim of the 14 x 16 km Pleistocene Amatitlan caldera. A cluster of dacitic lava domes occupies the southern caldera floor. The post-caldera Pacaya massif includes the Cerro Grande lava dome and a younger volcano to the SW. Collapse of Pacaya volcano about 1,100 years ago produced a debris-avalanche deposit that extends 25 km onto the Pacific coastal plain and left an arcuate somma rim inside which the modern Pacaya volcano (MacKenney cone) grew. A subsidiary crater, Cerro Chino, was constructed on the NW somma rim and was last active in the 19th century. During the past several decades, activity at Pacaya has consisted of frequent strombolian eruptions with intermittent lava flow extrusion that has partially filled in the caldera moat and armored the flanks of MacKenney cone, punctuated by occasional larger explosive eruptions that partially destroy the summit of the cone.
Information Contacts: Gustavo Chigna, Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hydrologia (INSIVUMEH), 7a Avenida 14-57, Zona 13, Guatemala City, Guatemala (URL: http://www.insivumeh.gob.gt/); Washington Volcanic Ash Advisory Center (VAAC), Satellite Analysis Branch (SAB), NOAA/NESDIS E/SP23, NOAA Science Center Room 401, 5200 Auth Road, Camp Springs, MD 20746, USA (URL: http://www.ssd.noaa.gov/).
Fuego
Guatemala
14.473°N, 90.880°W; summit elev. 3,763 m
All times are local (= UTC - 6 hours)
Guatemala
14.473°N, 90.880°W; summit elev. 3,763 m
All times are local (= UTC - 6 hours)
The current eruption from Fuego, located ~ 40 km WSW of the country's main airport (La Aura) and 17 km NE of the historic city of Antigua, has been ongoing since 2002. The Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (INSIVUMEH) monitors this volcano, providing regular observations. During the current reporting interval, 11 January 2008-12 January 2010, minor ash plumes were common, typically rising several hundred meters above the summit (tables 3 and 4). Some were incandescent. Plumes often drifted 5-15 km from the vent and residents in the region sometimes noted noise and shock waves. Observers occasionally saw avalanches and lahars, and sometimes an active lava flow traveled ~ 100 m from its vent. On 30 January 2009 observers saw incandescent material ejected 50-100 m above the crater and avalanches from the crater rim descended multiple ravines.
Table 3. Summary of reported activity at Fuego volcano for January 2008-December 2008. "--" indicates no activity. Information courtesy of INSIVUMEH, Washington Volcanic Ash Advisory Center (VAAC), and HIGP Thermal Alerts System.
Dates Explosions Ash Plumes
Altitude (km) Drift
Other observations
Altitude (km) Drift
Other observations
11 Jan 08 weak 4.1-4.3 --
Alert Level Yellow
Alert Level Yellow
24 Jan 08 shock waves detected 3 km away 4.2-4.5 S, SW, W
Avalanches of blocks traveled W towards Taniluya ravine; Alert Level lowered to Green
Avalanches of blocks traveled W towards Taniluya ravine; Alert Level lowered to Green
04 Feb 08 multiple 5 W
06-19 Feb 08 multiple 4-4.7 --
Fumarolic plumes
Fumarolic plumes
22-25 Mar 08 4-5/hour 4.1-4.6 6-8 km; S, SE
Noise/shock waves felt 5-8 km distant
Noise/shock waves felt 5-8 km distant
31 Mar-01 Apr 08 multiple -- SW
15-21 Apr 08 1-2/hour 4.3-4.7 5-8 km SW
Noise/shock waves felt 5-15 km distant
Noise/shock waves felt 5-15 km distant
28 Apr 08 1/hour 4.4 5 km SW
Noise audible 15 km distant
22-27 May 08 multiple 4.1-4.5 5 km SW
Noise/shock waves felt 10-15 km distant; constant avalanches of blocks traveled W towards
Taniluya and Santa Teresa ravines
Noise audible 15 km distant
22-27 May 08 multiple 4.1-4.5 5 km SW
Noise/shock waves felt 10-15 km distant; constant avalanches of blocks traveled W towards
Taniluya and Santa Teresa ravines
28-30 May 08 many 4.1-4.4 S, SW
Noise/shock waves felt several km away; avalanches of blocks traveled W into Taniluya and
Santa Teresa ravines
Noise/shock waves felt several km away; avalanches of blocks traveled W into Taniluya and
Santa Teresa ravines
02 Jun 08 -- -- --
Incandescent material ejected 50-100 m above crater; small lava flow traveled 100 m W
towards Santa Teresa ravine
Incandescent material ejected 50-100 m above crater; small lava flow traveled 100 m W
towards Santa Teresa ravine
13-17 Jun 08 -- 3.9-4.4 --
On 13 Jun lahars descended Santa Teresa (W) and Ceniza (SW) drainages; a lava flow
traveled 100 m towards Santa Teresa; on 15 Jun rumbling noises accompanied by shock
waves; on 17 Jun fumarolic plumes noted and incandescent material ejected ~50 m above
crater
On 13 Jun lahars descended Santa Teresa (W) and Ceniza (SW) drainages; a lava flow
traveled 100 m towards Santa Teresa; on 15 Jun rumbling noises accompanied by shock
waves; on 17 Jun fumarolic plumes noted and incandescent material ejected ~50 m above
crater
18 Jun 08 -- 4.3 W, SW
Incandescent material ejected 50 m above crater; constant avalanches of blocks traveled
W; rumbling/degassing noises
Incandescent material ejected 50 m above crater; constant avalanches of blocks traveled
W; rumbling/degassing noises
20 Jun 08 -- -- --
Lahar that was hot in areas descended Ceniza drainage to SW, dragging tree branches and
blocks 0.5-1 m in diameter
Lahar that was hot in areas descended Ceniza drainage to SW, dragging tree branches and
blocks 0.5-1 m in diameter
04 Jul 08 multiple -- --
Lava flow traveled 100 m W toward Santa Teresa ravine; lahar carrying blocks descended
Ceniza ravine to SW
Lava flow traveled 100 m W toward Santa Teresa ravine; lahar carrying blocks descended
Ceniza ravine to SW
7-8 Jul 08 many 4-4.5 S, SE, SW
Incandescence at summit; constant avalanches of blocks from lava-flow fronts descended W
flank
Incandescence at summit; constant avalanches of blocks from lava-flow fronts descended W
flank
31 Jul 08 -- -- --
Lahar descended El Jute River to SE
Lahar descended El Jute River to SE
01 Aug 08 many 4.1 W, SW
Rumbling noises and shockwaves occasionally accompanied explosions
Rumbling noises and shockwaves occasionally accompanied explosions
20 Aug 08 -- -- --
Lahars descended several rivers carrying blocks up to 1 m diameter
Lahars descended several rivers carrying blocks up to 1 m diameter
25-26 Aug 08 many 4.1 SW
300-m long lava flow traveled W towards Santa Teresa ravine
300-m long lava flow traveled W towards Santa Teresa ravine
18 Sep 08 -- 4.3 SSW
24 Sep 08 many 4.1 W
Lava flow traveled 300 m W towards Seca ravine; avalanches generated by lava flow front
Lava flow traveled 300 m W towards Seca ravine; avalanches generated by lava flow front
20-21, 25 Nov 08 many 4.1-4.6 W, S
Rumbling/degassing noises and shock waves detected 10 km away; lava flowed 150 m towards
Taniluya ravine; incandescent material rolled down flanks
Rumbling/degassing noises and shock waves detected 10 km away; lava flowed 150 m towards
Taniluya ravine; incandescent material rolled down flanks
12 Dec 08 many 4.1-5 SSW
Rumbling/degassing noises and shock waves detected 10 km away
Rumbling/degassing noises and shock waves detected 10 km away
Table 4. Summary of reported activity at Fuego volcano for January 2009-January 2010. "--" indicates no activity. Information courtesy of INSIVUMEH, Washington Volcanic Ash Advisory Center (VAAC), and HIGP Thermal Alerts System.
Dates Explosions Ash Plumes
Altitude (km) Drift
Other observations
Altitude (km) Drift
Other observations
4-6 Jan 09 multiple 4.1-5.1 12 and W, SW
Rumbling noises and shock waves detected 10 km away; constant avalanches of blocks
descended S and SW flanks
Rumbling noises and shock waves detected 10 km away; constant avalanches of blocks
descended S and SW flanks
8-9 Jan 09 3-5/hour 4.3-5.4 10-15 km; S, SW
Rumbling noises and shock waves detected 10-15 km away; constant avalanches of blocks
descended S and SW flanks
Rumbling noises and shock waves detected 10-15 km away; constant avalanches of blocks
descended S and SW flanks
19-20 Jan 09 many 4.1-4.6 7 km; W, W, SW
Some explosions produced rumbling sounds; avalanches occurred on S and SW flanks;
MODIS/MODVOLC thermal alerts 23 and 25 Jan
Some explosions produced rumbling sounds; avalanches occurred on S and SW flanks;
MODIS/MODVOLC thermal alerts 23 and 25 Jan
30 Jan, 3 Feb 09 multiple 4.1-4.7 S, SE
Some explosions produced rumbling sounds and shock waves; fumarolic plumes rose 100 m
above crater; on 30 Jan incandescent material ejected 50-100 m above crater and
avalanches from crater rim traveled down multiple ravines
Some explosions produced rumbling sounds and shock waves; fumarolic plumes rose 100 m
above crater; on 30 Jan incandescent material ejected 50-100 m above crater and
avalanches from crater rim traveled down multiple ravines
6, 8, 10 Feb 09 multiple 4.1-5.4 S, SW
Some explosions produced rumbling sounds; constant avalanches of blocks; MODIS/MODVOLC
thermal alerts 5 and 10 Feb
Some explosions produced rumbling sounds; constant avalanches of blocks; MODIS/MODVOLC
thermal alerts 5 and 10 Feb
20, 24 Feb 09 many 4.1-4.7 6-8 km SW
Some explosions produced rumbling sounds and shock waves; incandescent material ejected
150 m above crater; incandescent avalanches of blocks traveled down W and SW flanks
Some explosions produced rumbling sounds and shock waves; incandescent material ejected
150 m above crater; incandescent avalanches of blocks traveled down W and SW flanks
6, 10 Mar 09 many 4.2-4 12-15 km; S, SW
Some strong explosions produced rumbling sounds; shock waves detected 8 km away;
avalanches of blocks; MODIS/ MODVOLC thermal alerts 4 and 7 Mar
Some strong explosions produced rumbling sounds; shock waves detected 8 km away;
avalanches of blocks; MODIS/ MODVOLC thermal alerts 4 and 7 Mar
12, 16, 17 Mar 09 many 4.2-4.8 S, SW
Incandescent material ejected 75 m into air; some explosions produced rumbling noises
Incandescent material ejected 75 m into air; some explosions produced rumbling noises
27, 30 Mar 09 many 4.1-4.8 S, SW
Some explosions produced rumbling sounds; shock waves detected 10 kn away; avalanches of
blocks down W and SW flanks; on 30 Mar incandescent material ejected 75 m into air
Some explosions produced rumbling sounds; shock waves detected 10 kn away; avalanches of
blocks down W and SW flanks; on 30 Mar incandescent material ejected 75 m into air
24, 28 Apr 09 many 4.1-4.8 10 km SW
Some explosions produced rumbling sounds; shock waves detected 5 km away; avalanches of
blocks; fumarolic plumes rose 50-150 m and rifted S,NW, N; on 28 Apr incandescent
material ejected 75-100 m into air; MODIS/MODVOLC thermal alerts 7, 12, and 15 Apr
Some explosions produced rumbling sounds; shock waves detected 5 km away; avalanches of
blocks; fumarolic plumes rose 50-150 m and rifted S,NW, N; on 28 Apr incandescent
material ejected 75-100 m into air; MODIS/MODVOLC thermal alerts 7, 12, and 15 Apr
21 May 09 -- -- --
Lahars descended Santa Teresa and Ceniza ravines to W and SW, carrying blocks up to 2 km
diameter; MODIS/ MODVOLC thermal alert 16 May
Lahars descended Santa Teresa and Ceniza ravines to W and SW, carrying blocks up to 2 km
diameter; MODIS/ MODVOLC thermal alert 16 May
25-26 May 09 many 4.1-4.7 W, SW, S, SE
Some rumbling noises; on 25 May fumarolic plumes rose to 4.2 km and drifted S, SE
Some rumbling noises; on 25 May fumarolic plumes rose to 4.2 km and drifted S, SE
5, 8, 9 Jun 09 many 4.1-4.7 10 km; W, SW, S
Some rumbling noises; shock waves detected 12-15 km away; avalanches descended several
ravines; fumarolic plumes rose 100 m and drifted S, SW
Some rumbling noises; shock waves detected 12-15 km away; avalanches descended several
ravines; fumarolic plumes rose 100 m and drifted S, SW
10, 14 Jul 09 many 4.1-4.6 10-15 km; W, SW
Some rumbling noises and shock waves; incandescent material ejected 75 m and avalanches
descended several ravines; fumarolic plumes rose 100 m and drifted S, SW
Some rumbling noises and shock waves; incandescent material ejected 75 m and avalanches
descended several ravines; fumarolic plumes rose 100 m and drifted S, SW
31 Jul, 3 Aug 09 many 4-4.6 W
Some rumbling noises; incandescent materials ejected 75 m; avalanches occurred; fumarolic
plumes rose 200 m and drifted W, NW
Some rumbling noises; incandescent materials ejected 75 m; avalanches occurred; fumarolic
plumes rose 200 m and drifted W, NW
2-3 Aug 09 frequency increased -- --
MODIS/MODVOLC thermal alert 7 Aug
MODIS/MODVOLC thermal alert 7 Aug
21, 25 Aug 09 many 4.2-4.6 5-7 km; W, SW
On 21 Aug rumbling noises accompanied by incondescent tephra ejected 75 m high;
MODIS/MODVOLC thermal alert 31 Aug
On 21 Aug rumbling noises accompanied by incondescent tephra ejected 75 m high;
MODIS/MODVOLC thermal alert 31 Aug
10, 14 Sep 09 many 4.1-4.7 10 km; W, SW, S
Some explosions accompanied by rumbling noises and shock waves; incandescent material
ejected 100 m high; avalanches descended multiple ravines
Some explosions accompanied by rumbling noises and shock waves; incandescent material
ejected 100 m high; avalanches descended multiple ravines
9, 12, 13 Oct 09 many 4.1-4.6 W
Rumbling noises; avalanches of blocks; on 9 Oct lahar traveled down Lajas ravine carrying
blocks up to 50 cm in diameter
Rumbling noises; avalanches of blocks; on 9 Oct lahar traveled down Lajas ravine carrying
blocks up to 50 cm in diameter
21 Oct 09 -- -- 55 km S
26 Oct 09 many 4.4-4.8 10 km; S, SW
Rumbling/degassing sounds; avalanches of blocks
Rumbling/degassing sounds; avalanches of blocks
13 Nov 09 many 4.2-4.7 7 km S
Rumbling noises and incandescence noted; white fumarolic plumes rose 100 m and drifted
S, SW.
Rumbling noises and incandescence noted; white fumarolic plumes rose 100 m and drifted
S, SW.
30 Nov-1 Dec 09 many 4.3-4.7 8-15 km; W, SW
Rumbling noises noted; incandescent block avalanches generated; MODIS/MODVOLC thermal
alerts 24, 25, and 29 Nov
Rumbling noises noted; incandescent block avalanches generated; MODIS/MODVOLC thermal
alerts 24, 25, and 29 Nov
4 Dec 09 multiple 4.2-4.7 15-18 km W
Rumbling noises and incandescent block avalanches noted
Rumbling noises and incandescent block avalanches noted
11, 14, 15 Dec 09 many 4.1-4.7 8-12 km; W, SW
Incandescence from main crater and rumbling noises noted; avalanches descended S and W
flanks; MODIS/MODVOLC thermal alert 31 Dec
Incandescence from main crater and rumbling noises noted; avalanches descended S and W
flanks; MODIS/MODVOLC thermal alert 31 Dec
8, 11, 12 Jan 10 many 4-4.7 10 km; multiple
Incandescent material ejected to heights up to 75 m; some explosions accompanied by
rumbling noises and shock waves felt up to 7 km away; avalanches descended flanks;
MODIS/MODVOLC thermal alerts 5, 6, and 12 Jan
Incandescent material ejected to heights up to 75 m; some explosions accompanied by
rumbling noises and shock waves felt up to 7 km away; avalanches descended flanks;
MODIS/MODVOLC thermal alerts 5, 6, and 12 Jan
Observations. A report from Michigan Technological University described multi-instrument fieldwork during 9-21 January 2009 (Nadeau and Dalton, 2009), work often amid conditions of poor visibility. The authors also credited seven other people (from INSIVUMEH and PCMI; see Information Contacts) who participated in the campaign. One of the instruments deployed was an ultraviolet (UV) camera that enabled researchers to measure SO2 emission rates with high temporal resolution. They also took concurrent seismic and infrasonic acoustic measurements, some mini-DOAS measurements, and they recorded their visual observations of volcanism. A similar campaign occurred in January 2008.
During this fieldwork, activity was dominated by passive degassing accompanied by intermittent tephra eruptions of variable size (figure 12). Explosions ranged from small puffs of ash that mixed with the passive gas plume to larger, convective columns with ejected bombs.
Figure 12. Passive degassing (left) and an explosion (right) at Fuego, December 2008-January 2009. From Nadeau and Dalton (2009).
During 9-21 January 2009, the UV camera was placed on Meseta ~ 1 km from the erupting vent (figures 13 and 14). An array seismo-acoustic stations was also deployed around the circumference of the vent for full azimuthal coverage. Thick clouds prohibited visibility on most days, resulting in collection of imagery on only 3 dates (12, 14, and 21 January). On 21 January several stationary mini-DOAS (differential optical absorption spectroscopy) scans of the passively degassed plume were also made for comparison with SO2 retrievals from camera images.
Figure 13. Vertical aerial photo the Fuego summit (steaming, near the bottom) and Meseta edifice. Star indicates location of UV camera during field measurements. (inset) UV camera and plume as seen from measurement site. From Nadeau and Dalton (2009).
Figure 14. A map of SO2 concentration-pathlength created from UV imagery of Fuego during the 2009 campaign. Scale bar at bottom indicates concentration pathlength in colored versions (in units of ppm-m with highest values on the scale and in portions of the plume at ~ 1,000 ppm-m). From Nadeau and Dalton (2009).
Preliminary evaluation of camera-derived emissions at Fuego in January 2009 show decreases in SO2 output prior to explosive events, and may indicate short-term sealing of the vent. Additionally, some small low-frequency seismic events without explosion signals in the acoustic record were associated with short-term increases in SO2 output.
A paper presented by Lyons, Waite, and Rose (2009) suggests the potential to track activity of Fuego volcano using explosive energy partitioning. This has implications for monitoring and hazard prediction.
Geologic Summary. Volcan Fuego, one of Central America's most active volcanoes, is one of three large stratovolcanoes overlooking Guatemala's former capital, Antigua. The scarp of an older edifice, Meseta, lies between 3,763-m-high Fuego and its twin volcano to the north, Acatenango. Construction of Meseta volcano dates back to about 230,000 years and continued until the late Pleistocene or early Holocene. Collapse of Meseta volcano may have produced the massive Escuintla debris-avalanche deposit, which extends about 50 km onto the Pacific coastal plain. Growth of the modern Fuego volcano followed, continuing the southward migration of volcanism that began at Acatenango. In contrast to the mostly andesitic Acatenango volcano, eruptions at Fuego have become more mafic with time, and most historical activity has produced basaltic rocks. Frequent vigorous historical eruptions have been recorded at Fuego since the onset of the Spanish era in 1524, and have produced major ashfalls, along with occasional pyroclastic flows and lava flows.
References. Nadeau, P., and Dalton, M., 2009, Report on UV camera field campaign, Fuego and Santiaguito volcanoes, Guatemala, December 2008-January 2009, unpublished informal report accessed January 2010 (URL: http://www.geo.mtu.edu/~panadeau/)
Lyons, J.J., Waite, G.P., and Rose, W.I., 2009, Variable explosive energy partitioning during open vent activity at Fuego volcano, Guatemala 2007-2009: Constraining explosion source processes and implications for monitoring, American Geophysical Union 2009 Fall Meeting Abstract V23D-2124.
InformationContacts: Instituto Nacional de Sismologia, Vulcanologia, Meteorologia e Hidrologia (INSIVUMEH) (National Institute of Seismology, Volcanology, Meteorology and Hydrology), Ministero de Communicaciones, Transporto, Obras Publicas y Vivienda, 7a. Av. 14-57, zona 13, Guatemala City 01013, Guatemala (URL: http://www.insivumeh.pagina.de); Washington Volcani Ash Advisory Center (VAAC) (URL: http://www.ssd.noaa.gov/VAAC/messages.html); MODIS/MODVOLC Thermal Alerts, Hawai'i Institute of Geophysics and Planetology (HIGP) Thermal Alerts System, School of Ocean and Earth Science and Technology (SOEST), Univ. of Hawai'i, 2525 Correa Road, Honolulu, HI 96822, USA (URL: http://hotspot.higp.hawaii.edu/);Gregory Waite, John Lyons, Patricia Nadeau, Marike Dalton, and Joshua Richardson, Michigan Technological University, Department of Geological and Mining Engineering and Science, Houghton, MI, USA (URL: http://www.geo.mtu/edu/rs4hazards/; Email: http://www.geo.mtu.edu/~panadeau/ and http:/www.geo.mtu.edu/~mpdalton/); Kyle Brill, Jemile Erdem, and Jesse Silverman, PCMI (Peace Corps, Master's International Program), Michigan Technological University; Amilcar Cardenas (INSIVUMEH).
Cleveland
Aleutian Islands, USA
52.825°N, 169.944°W; summit elev. 1,730 m
All times are local (= UTC - 10 hours)
Cleveland, an Aleutian Islands volcano situated almost 1,500 km S of the E margin of the Bering strait, had multiple short-duration ash-bearing explosive eruptions in 2009. The first of these documented eruptions took place on 2 January 2009 (BGVN 33:11). The next two documented ash-bearing eruptions occurred on 25 June and 2 October 2009 (BVGN 34:10). As stated in those previous issues, thermal anomalies were common in satellite data as reported by the Alaskan Volcano Observatory (AVO).
Previously not reported was a possible fourth 2009 eruption, which took place on 12 December. It seemingly generated a diffuse ash plume, an event detected a few days later in satellite imagery (figure 15). AVO had also lowered the hazard status on 12 December to "Unassigned," a level that results from the lack of a nearby seismic receiver and the consequent inability to define background seismicity. As of late January 2010, further activity at Cleveland was absent and no further reports were issued.
Figure 15. A MODIS satellite image of Cleveland volcano and vicinity captured at 2237 UTC on 12 December 2009 (brightness temperature difference from Channel 31 minus Channel 32). The plume (at tip of horizontal arrow) was judged as likely due to an eruption but this was not certain. N is towards the top and for approximate scale, the adjacent (Nikolski) island outlined to the E is ~ 100 km long (for other maps, see BGVN 33:07 and 26:01). Courtesy of John Dehn, AVO (arrows added).
John Dehn of AVO provided more details regarding the discovery and interpretation of the 12 December plume (figure 17). It was initially detected by David J. Beberwyk at the Air Force Weather Agency (AFWA). The information was passed to AVO and distributed to staff on 14 December. After looking at the imagery, they announced in log entries on 15 December that they had possibly missed the faint signal in their daily reporting. Dehn was "pretty confident that this [was] real but the signal is comparable to weather systems."
Dehn went on to note that "Cleveland is known for these small events, and whether we catch them is up to the fortuitousness of a satellite pass and good weather. No further activity was reported, though [AVO's] Rick Wessels noted that a MODIS image from a few hours later shows possible dark deposits on the NW side of the summit. The summit of the volcano has typically had dark deposits on the snow in recent years as we've seen on the webcam, satellite imagery and observer reports so this [was] not conclusive."
Geologic Summary. Beautifully symmetrical Mount Cleveland stratovolcano is situated at the western end of the uninhabited, dumbbell-shaped Chuginadak Island. It lies SE across Carlisle Pass strait from Carlisle volcano and NE across Chuginadak Pass strait from Herbert volcano. Cleveland is joined to the rest of Chuginadak Island by a low isthmus. The 1,730-m-high Mount Cleveland is the highest of the Islands of the Four Mountains group and is one of the most active of the Aleutian Islands. The native name for Mount Cleveland, Chuginadak, refers to the Aleut goddess of fire, who was thought to reside on the volcano. Numerous large lava flows descend the steep-sided flanks of the volcano. It is possible that some 18th-to-19th century eruptions attributed to Carlisle should be ascribed to Cleveland (Miller et al., 1998). In 1944 Cleveland produced the only known fatality from an Aleutian eruption. Recent eruptions from Mount Cleveland have been characterized by short-lived explosive ash emissions, at times accompanied by lava fountaining and lava flows down the flanks.
Information Contacts: Alaska Volcano Observatory (AVO), a cooperative program of the U.S. Geological Survey, 4200 University Drive, Anchorage, AK 99508-4667, USA; Geophysical Institute, University of Alaska, PO Box 757320, Fairbanks, AK 99775-7320, USA; and Alaska Division of Geological & Geophysical Surveys, 794 University Ave., Suite 200, Fairbanks, AK 99709, USA (URL: http://www.avo.alaska.edu/).
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