************************************** From: Shellie Rose <srr13@xxxxxxxx> ************************************** The eruption and emplacement of a long lava flow continues at Klyuchevskoy Volcano on the Kamchatka Peninsula, Russia. This activity is being closely monitored by the Kamchatka Volcanic Eruption Response Team (KVERT), and more remotely by the University of Pittsburgh using the ASTER imaging instrument on the NASA Terra satellite. To support this effort, the ASTER urgent request protocol has been utilized several times since February. The spaceborne ASTER data are 15m/pixel in the visible/near infrared (VNIR), 30 m/pixel in the shortwave infrared (SWIR), and 90m/pixel in the thermal infrared (TIR) regions. Data can be acquired as day/night pairs (~ 36 hour separation) once per week at this latitude. The most recent (28 and 29 May) data can be seen here: http://ivis.eps.pitt.edu/data/Kamchatka/28May2007_Klyuch.pdf http://ivis.eps.pitt.edu/data/Kamchatka/29May2007_Klyuch.pdf Eruption Summary to Date: A weak thermal anomaly at the summit of Klyuchevskoy, was first identified by KVERT on 14 Dec 2006. The color code was initially raised from yellow to orange on 15 January 2007 due to increased ash explosions, gas/steam plumes, and increasing volcanic tremor. Over the past five months, the summit thermal anomaly has intensified with strombolian activity and the eruption of a lava flow that extends 4 km down the northern flank. This emplacement produced numerous lahars up to 3 km long as well as small ash plumes at the flow toe due to rock fall. Steadily increasing temperatures (initially ~10 C above background) have resulted in saturation of the ASTER TIR and subsequently the SWIR subsystems. Furthermore, consistent saturation suggests that effusive activity from the summit crater has been continuous and well established. ASTER data from 26 and 27 April revealed increasing thermal output and the first occurrence of saturated pixels since the initial cloud-free view of the summit on 21 Feb. On 16 May the color code was raised to red by KVERT with the detection of a strong tremor and the potential for large (10 km ASL) ash plumes. ASTER data acquired on 12 and 13 May and 28 and 29 May, show a changing lava flow pattern, numerous saturated pixels, and dynamic ash/steam plumes. Recent History: The 28 May VNIR data show an optically-thick plume originating from the summit crater and extending southeast off the image (greater than 22 km). The 29 May nighttime TIR data reveals a discontinuous plume extending west off the image (greater than 40 km). A TIR decorrelation stretch of both the day and night data indicates that the plume is composed primarily of water/ice with lesser amounts of ash and very little SO2. Ash is concentrated proximally and lessens with distance, ultimately suggesting that fallout is concomitant with plume migration. A significant increase in thermal output has been detected by ASTER since February with the number of thermally elevated and saturated pixels more than tripling. The ASTER TIR data from 29 May show a complex thermal anomaly consisting of 3 flows radiating from the summit and measuring 3.6 km by 500 m, 2.2 km by 90 m, and 4.6 km by 180 m. Maximum temperatures extracted from the central and eastern anomalies are well below saturation (22 C) near the summit and decrease to ~10 C above background (-18.8 C) down slope. These surfaces are too cool to be detectable in the SWIR and are most likely caused by the presence of melt water and/or lahar activity. The size and thermal output of the main open-channel lava flow to the west is causing 56 TIR pixels (0.45 sq. km) to be at or above the saturation level (> 97 C). This is an increase of 24 saturated pixels from what was observed in the 12 and 13 May data. KVERT reports have upgraded explosivity from strombolian (as recent as 4 May) to reflect vulcanian type activity between 17 May and 25 May, accompanied by lava flow effusion along the northwestern flank. The ASTER SWIR data collected on 29 May reveal significant thermal output over the lava flows. The maximum non-saturated brightness temperature derived from the SWIR data ranges from 370 C around the perimeter to 464 C near the central, saturated pixels. Over 100 SWIR pixels within the flow were saturated. Incandescence was detected in the VNIR data on 26 April in two distinct open lava channels, one to the north and one to the northwest. However, in the 12 May VNIR data no incandescence was detected in the northwestern lava channel. The latest acquisition reveals that a ~200 m long area of incandescence is now present in a 4.6 km long thermally elevated area extending from the summit, lending support for the formation of a new lava flow to the north-northeast with an associated lahar near the toe. Incandescence continues to be easily detectable in the main northern channel, suggesting primary lava effusion has remained concentrated there. The numerous saturated pixels still present in the low gain mode of ASTER SWIR coupled with the incandescence seen in the VNIR data should allow brightness temperatures to be extracted from ASTER VNIR band 3 (0.0807 microns) data. This band in the normal gain mode has a detectable temperature range from 705-973 C. Furthermore, the flow location on the northern and continuously shadowed side of the volcano together with the low sun angle allows for a relatively easy correction for solar reflected energy at this wavelength. Brightness temperatures extracted from the atmospherically-corrected 15 m/pixel data showed no saturation. The maximum temperatures recorded in the lava channel were 800 C. ASTER will continue to monitor the volcano to assess changes in the thermal and gas flux throughout this phase of activity. New ASTER day/night data acquisitions are scheduled for the 5/6 June, 13/14 June, and 21/22 June. Shellie Rose srr13@xxxxxxxx Michael Ramsey mramsey@xxxxxxxx ------------------------------------------------- Shellie Rose University of Pittsburgh Department of Geology and Planetary Science SRCC 200 Pittsburgh, PA 15260 ============================================================== To unsubscribe from the volcano list, send the message: signoff volcano to: listserv@xxxxxxx, or write to: volcano-request@xxxxxxxx To contribute to the volcano list, send your message to: volcano@xxxxxxxx Please do not send attachments. ==============================================================
