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Klyuchevskoy Activity Continues
From: Shellie Rose <roseshellie@xxxxxxxxx>
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The Advanced Spaceborne Thermal Emission and Reflection Radiometer
(ASTER) in conjunction with the Urgent Request Protocol (URP)
continues to provide visible near infrared (VNIR) and thermal infrared
(TIR) data of the frequently active Klyuchevskoy volcano on the
Kamchatka Peninsula of far-eastern Russia. The ASTER instrument is
made up of three subsystems each with different spatial and spectral
resolutions with the capability of acquiring both day and nighttime
datasets. Data are 15m/pixel in the VNIR, 30 m/pixel in the SWIR, and
90m/pixel in the TIR regions. Unfortunately, the SWIR subsystem is no
longer acquiring data due to a cryo-cooler malfunction.
The Kamchatka Volcanic Eruption Response Team (KVERT) reported the
onset of activity in August of 2009. Since that time, ASTER has been
acquiring data in a rapid response mode and Klyuchevskoy has produced
strombolian explosions, gas/steam/ash plumes and effusive lava flows
from the summit crater. The University of Pittsburgh’s Image
Visualization and Infrared Spectroscopy (IVIS) Laboratory has
processed the relatively cloud-free ASTER acquisitions in 2010 and a
summary of activity can be found here:
http://ivis.eps.pitt.edu/data/Kamchatka/Klyuch2010eruptionVNIR.pdf
http://ivis.eps.pitt.edu/data/Kamchatka/Klyuch2010eruptionTIR.pdf
KVERT first reported increased seismic activity at the beginning of
August, 2009. However, strombolian explosions were not reported until
mid-September. Lava effusion from the summit crater and down the
east-southeastern flank initiated in mid-November that was also
concomitant with explosive activity primarily in the summit crater.
Typically, the previous eruptions of 2005 and 2007 produced effusive
lava flows down the Krestovsky channel on the northwestern flank
before initiating additional lava flows to the north, east, and
southeast. The VNIR dataset presented here was acquired on February
13. 2010 and shows that effusive activity to the east-southeast had
ceased and cooled by this time as indicated by snow cover on the
flanks. This dataset also shows that effusive activity migrated to
the Krestovsky channel and significant plumes extend tens of
kilometers. Most notably, incandescent lava is present near the
summit crater and partially obscured by the opaque eruption plume.
The sequence of TIR data include the pixel integrated brightness
temperatures of the ambient surface and thermal anomalies associated
with active volcanism. KVERT reported effusion of lava into the
Krestovsky channel in January along with phreatic bursts at the front
of the flows and ash fall reported as far as the town of Klyuchi, 30
km to the north. A lava flow was seen in the Mach 9th image
travelling in a new direction (to the west). By the end of March, a
new pulse of lava was observed travelling down the Krestovsky channel.
However, 10 days later another new flow direction (to the southwest)
can be seen. Flows to west and southwest remain currently active.
Based on the ASTER TIR data, the active lava flows extended up to ~2.5
km in length and ~270 m wide. The associated pixel integrated
brightness temperatures exceed the maximum sensitivity of the TIR
sensor (> 97 ºC) suggesting open channel flows are present. From
March 9 until present, a small linear thermal feature along the
northern flank appears to be a lahar with temperatures ranging from
-36 ºC to -13 ºC. A decorrelation stretch (DCS) performed on the TIR
dataset of the February 13 acquisition indicates that the eruption
plume is primarily composed of ash and SO2 throughout, and traces of
steam (H2O) confined to the summit crater. The lava flows also
indicate significant quantities of steam production suggesting that
the lava-ice interaction is producing phreatic activity along the
interface. Phreatic activity was reported by KVERT at the fronts of
these flows lending support to the observations collected from the
ASTER data.
ASTER will continue to monitor the volcano to assess changes in the
thermal, ash, and gas flux throughout this phase of activity.
Shellie Rose and Michael Ramsey (University of Pittsburgh)
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