Cascade Range Current Update |
U.S. Geological Survey, Vancouver, Washington
University of Washington, Pacific Northwest Seismograph Network, Seattle, Washington
Current status is Volcano Alert (Alert Level 3); aviation color code
RED Seismicity overnight has remained at very low levels. After the
vigourous steam-and-ash emission of yesterday morning,
seismicity dropped with individual events becoming smaller. By
about 5 p.m. PDT yesterday, individual events became rare and as
of 11:00 p.m., seismicity has been stable at a low level. Yesterday, field crews continued to harden GPS sites for the
approaching winter and retrieved data. The GPS sites on the
dome survived the steam-and-ash emission and data are being
received and processed at the observatory. The station on the
northern flank of the dome, shows a trend of northward
displacement totaling 2 cm in the last three days. This is the same
sense of movement recorded by the nearby station that was
destroyed by the first steam-and-ash emission on 1 October. Data
from the other two stations on the dome, which were installed on 4
October are currently being analyzed. Data from GPS instruments
on the outer flanks of the volcano show no movement of the outer
flanks. No gas measurements were made yesterday. A seismic crew
installed an additional broadband seismometer on the northwest
flank of the volcano which will help show a broader range of
seismic energy release. With the help of the U.S. Forest Service,
field crews installed an antenna mast for a VSAT uplink which will
improve our ability to retrieve data from the field. It began raining t the mountain at about 7:30 p.m. PDT. By about
9:30 p.m. about 0.1 inch of rain had fallen. Overnight, the acoustic
flow monitoror (AFM) in the crater indicated that several small
debris flows had moved past the site. By midnight, higher flows
were recorded at a station on the pumice plain, but none were
large enough to trigger an automatic alert. We expect these types
of flowage events to recur during intense rainstorms. Wind forecasts from the National Oceanic and Atmospheric
Administration (NOAA), combined with eruption models, show
winds this morning are from the west-southwest such that any ash
clouds will drift to the east-northeast. We continue to monitor the situation closely and will issue
additional updates and Alert Level changes as warranted. Press conferences will continue to be held at the Headquarters
office of the Gifford Pinchot National Forest. The morning press
conference is at 9:30 AM. If activity remains low, we will do a
show-and-tell of some of the instruments were are using to monitor
the volcano at the press conference.
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