****************************************** From: Michael Ramsey <mramsey@xxxxxxxx> ****************************************** Bezymianny volcano (55.9N, 160.6E, ~2900 m elevation) erupted on 11 May 2007 at approximately 14:30 UTC (KVERT report, 2007) and is at Color Code Yellow (as of 18 May). The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), collecting data in an urgent request mode for the ongoing eruption of nearby Kyluchevskoy volcano, also captured remarkable images of the initial stages of the Bezymianny eruption. Data were collected on 12 (daytime) and 13 (nighttime) May, however only data collected on the 12th are presented here due to heavy cloud cover on the night of the 13th of June. A figure has been created and staged at the IVIS website to accompany the text: http://ivis.eps.pitt.edu/data/Kamchatka/12May2007_Bezy.pdf Visible/near infrared (VNIR) observations: Approximately 40% of the summit region was visible in the 15 m/pixel VNIR image. A plume of steam and ash was observed trending over 20 km northeast into the surrounding non-volcanic clouds. It is speculated that ash from earlier (min-hours) eruptions of Bezymianny was detected over 60 km to the northeast. It is here where the ash plume mixes with the water-ice plume from Kyluchevskoy. On the upper southwestern part of the dome, a bright steam covered area was observed. This region spans ~0.13 km² and is close to the dome's central summit in an area of persistently active fumaroles. Shortwave infrared (SWIR) observations: A strong SWIR thermal anomaly (30 m/pixel) was observed on the upper dome, near the fumaroles and extended down the southwestern side of the existing lava dome. The radiance from band 7 (2.26 micrometers) was corrected for solar reflection by subtracting the non-volcanic background value. From these data, a maximum derived temperature was found to be ~355 C. These high pixel-integrated brightness temperatures indicate that a new lava lobe is being em placed at the surface. Thermal infrared (TIR) observations: The brightest thermal anomaly in the TIR (90 m/pixel) was located on the southwest part of the upper dome in the same area as the SWIR-derived maximum temperature. A maximum atmospherically-corrected TIR brightness temperature of 41 C was recorded, which was approximately 49 C above the non-volcanic background temperature of -8 C. ASTER will continue to monitor the volcano throughout this phase of activity. New ASTER day/night data acquisitions are scheduled for the 20/21 May and the 28/29 May and will continue weekly throughout June. In addition, a field investigation is scheduled for August 2007 to investigate the surface deposits. Cited reference: KVERT report. 17 May 2007. http://www.avo.alaska.edu/activity/avoreport.php? view=kaminfo&id=245&type=kaminfo&month=May&year=2007 "The explosive eruption occurred at Bezymianny volcano, probably, from 14:30 till 15:00 UTC on May 11. Clouds obscured the volcano from May 13 till present. According to information by hunters, a large mud flow 200 m in width moved along the Sukhaya Khapitsa river at Bezymianny volcano area on May 17. Probably pyroclastic flow deposits caused a mud flow. According to satellite data, a size of thermal anomaly over the lava dome decreased from 10-25 pixels (on 8-12 May) till 1-4 pixels (on 15-17 May)." Adam Carter ajc44@xxxxxxxx website: http://www.pitt.edu/~ajc44 Michael Ramsey mramsey@xxxxxxxx Shellie Rose srr13@xxxxxxxx +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Dr. Michael Ramsey, Associate Professor ** sabbatical address (1 May - 31 Aug 2007) ** Alaska Volcano Observatory U.S. Geological Survey Alaska Science Center 4200 University Drive, room 210 Anchorage, AK 99508 office: 907-786-7111; fax: 907-786-7425 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ============================================================== 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. ==============================================================
