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Volcano activity of December 20, 2012
(Before It's News)
The best independent earthquake reporting website in the world
This (almost) daily post intends to follow up the activity changes of volcanoes all over the world.
This post is written by geologist Richard Wilson who specializes in Volcano seismicity and Armand Vervaeck. Please feel free to tell us about new or changed activity if we haven’t written about it. -
December 20, 2012 volcano activity
My reports will be rather spotty the next few days as we will be traveling. I will try to keep abreast of any significant volcanic activity and report on it, but not the usual day to day low-level stuff until around Christmas when we return. Rodger
Amplitude of volcanic tremor at Plosky Tolbachik (Kamchatka Peninsula) is “through the roof”. KVERT reports that tremor amplitude is nearly four times what it was a week ago. My interpretation is that magma feeding channels are narrowing (due to cooling and congealing of lava within them), but magma supply continues to be high. It’s the old water hose effect where when you place your thumb across the hose outlet, the water squirts out with more force. I have included a MODIS satellite shot of the eruption (taken two weeks ago).
Tungurahua volcano (Ecuador) remains in full eruption, producing ashfalls on surrounding communities, loud roars and detonations, occasional pyroclastic flows (which reached 4 km from the crater earlier this week), and the continued threat of lahars if/when rainfall should increase. EPN reports the ash plume over the volcano hovers around 2 km height today.
Elsehere, earthquake activity has further increased at or near Katmai volcano (AK) (station KBM) during the past 24 hours. Swarm activity is fairly frequent beneath the entire volcano cluster, making it difficult to assess what a “normal” level of earthquake activity truly is at the volcanoes.
Small deep (12-17 km) earthquakes continue beneath Mammoth Mountain volcano (CA) (station MRD). The larger events (red) on the Mammoth record are actually centered beneath the Sierra Nevada immediately south of Long Valley caldera.
Emissions of gas and ash at Popocatepetl volcano (Mexico) have increased through the week and now occur an average of nearly one exhalation per every 20 minutes! The Popo seismogram shows low-level volcanic tremor and possibly some very small local earthquakes.
Pacaya volcano (Guatemala) (station PCG) perks with numerous small volcanic earthquakes and occasional pulses of (small explosion?) tremor. The volcano experienced a small ash eruption two days ago. Lava continues to descend from the summit of Fuego volcano (station FG3) (see volcanocam photo). Small avalanches of incandescent blocks occasionally collapse from the front of the lava flow (see dust cloud in photo). Relatively strong volcanic tremor accompanies degassing at Santa Maria volcano (STG6). Remember, the “spikey” appearance of the record is due to seismic equipment malfunction, not the volcano.
Periods of banded volcanic tremor continue at San Cristobal volcano (Nicaragua) (station CRIN). A period of elevated tremor also occurred at nearby Masaya volcano (station MASN) overnight.
Small volcanic earthquakes rattle Nevado Del Ruiz volcano (Colombia) (station OLLZ) today.
Eruption seismicity remains relatively subdued at Reventador volcano (Ecuador) (station CONE), perhaps in deference to activity at “The Black Giant” Tungurahua.
Amplitudes of local earthquakes have increased at Tongariro and Ruapehu volcanoes (New Zealand), while volcanic tremor has diminished slightly at White Island volcano.
Recent satellite imagery shows pronounced SO2-enriched plumes issuing from Popocatepetl, Tungurahua and Nyiragongo (DRC) volcanoes. An Aleutian low pressure system is also lifting the eruptive plume from Tolbachik to heights where it can be “seen” by satellite sensors.
2012-12-20 14:05:30
Source: http://earthquake-report.com/2012/12/20/volcano-activity-of-december-20-2012/
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