Redoubt Volcano, AK (103 miles southeast of Anchorage): Beginning Sunday morning, nearly continuous volcanic tremors have been recorded at stations near Redoubt's summit, prompting the Alaskan Volcano Observatory (AVO) to raise the Aviation Color Code to ORANGE and the Alert Level to WATCH. Although seismicity close to the volcano's summit has declined somewhat, the current activity at Redoubt could be precursory to an eruption, perhaps within days. The State of Alaska and the AVO continue to monitor the situation
"The 1989-90 eruption of Redoubt seriously affected the populace, commerce, and oil production throughout the Cook Inlet region and air traffic as far away as Texas. Total estimated economic costs are $160 million (Tuck and others, 1992), making the eruption the of Redoubt the second most costly in U.S. history."
"Redoubt Volcano is a stratovolcano located within a few hundred kilometers of more than half of the population of Alaska. This volcano has erupted explosively at least six times since historical observations began in 1778. The most recent eruption occurred in 1989-90 and similar eruptions can be expected in the future. The early part of the 1989-90 eruption was characterized by explosive emission of substantial volumes of volcanic ash to altitudes greater than 12 kilometers above sea level and widespread flooding of the Drift River valley. Later, the eruption became less violent, as developing lava domes collapsed, forming short-lived pyroclastic flows associated with low-level ash emission.
Clouds of volcanic ash had significant effects on air travel as they drifted across Alaska, over Canada, and over parts of the conterminous United States causing damage to jet aircraft. Economic hardships were encountered by the people of south-central Alaska as a result of ash fallout. Based on new information gained from studies of the 1989-90 eruption, an updated assessment of the principal volcanic hazards is now possible. Volcanic hazards from a future eruption of Redoubt Volcano require public awareness and planning so that risks to life and property are reduced as much as possible."
Originally posted by ll__raine__ll
whoa freaky. here everyone is watching yellowstone and all activity is happening up there.
have there been any public warnings or evacuation alerts?
Unrest at Redoubt Volcano continues. Seismicity has waxed and waned over the past 24 hours, but remains well above background levels.
Nothing unusual has been seen over the past 24 hours in partly cloudy satellite views. AVO conducted a gas-measurement flight yesterday afternoon, and detected elevated values of SO2 venting from the volcano's summit crater. Observers also saw new outflows of muddy debris alongside the glacier that is downslope of the summit; these were not seen the previous day (Sunday, January 25).
The current activity at Redoubt could be precursory to an eruption, perhaps within days. A further increase in seismicity is expected to accompany an eruption.
Originally posted by ll__raine__ll
hmm ... fingers crossed it doesn't happen or everyone gets out.
i always wonder why people live near volcanoes and forget NZ is on top of one of the biggest in the world. oops.
M 1.0, Southern Alaska
Date: Tuesday, January 27, 2009 09:23:15 UTC Tuesday, January 27, 2009 12:23:15 AM at epicenter
Depth: 0.50 km (0.31 mi)
M 1.8, Southern Alaska
Date: Friday, January 23, 2009 22:38:20 UTC Friday, January 23, 2009 01:38:20 PM at epicenter
Depth: 115.20 km (71.58 mi)
Southern Alaska Date: Tuesday, January 27, 2009 01:48:42 UTC Monday, January 26, 2009 04:48:42 PM at epicenter
Depth: 100.00 km (62.14 mi)
M 1.8, Southern Alaska
Date: Thursday, January 22, 2009 10:33:36 UTC Thursday, January 22, 2009 01:33:36 AM at epicenter
Depth: 101.40 km (63.01 mi)
The 10,197-foot peak 100 miles southwest of Anchorage now appears ready to explode for the second time in 20 years, the observatory noted in a mid-day status report.
If history is a guide, Redoubt should erupt in style, geologists say. Unlike volcanoes in Hawaii, which tend to ooze out slow-rolling lava, volcanoes in Alaska -- Redoubt included -- usually erupt explosively, shooting ash nearly eight miles high.
Were that to happen around 9 a.m. this morning, the forecasted winds would carry the ash plume directly toward Anchorage, according to a chart posted on the Alaska Volcano Observatory Web site Tuesday. (See adn.com/volcano) The warning prompted both state and city emergency agencies to issue bulletins to residents with advice on how to cope with an ash storm.
The state said Tuesday afternoon that the Drift River Oil Terminal's volcano readiness plan is now in effect.
Apart from possibly affecting climate, volcanic clouds from explosive eruptions also pose a hazard to aviation safety. This was brought to attention during the 1982 eruption of Galunggung in Java; two Boeing 747 flew into the ash cloud, suffering temporary engine failure and structural damage. During the past two decades, more than 60 airplanes,
In recorded history, explosive eruptions at subduction zone (convergent-boundary) volcanoes have posed the greatest hazard to civilizations. Subduction-zone stratovolcanoes like Mount St. Helens and Mount Pinatubo typically erupt with explosive force, because the magma is too stiff to allow easy escape of volcanic gases. As a consequence, tremendous internal pressures mount as the trapped gases expand during ascent, before the pent-up pressure is suddenly released in a violent eruption. Such an explosive process can be compared to putting your thumb over an opened bottle of a carbonated drink, shaking it vigorously, and then quickly removing the thumb. The shaking action separates the gases from the liquid to form bubbles, increasing the internal pressure. Quick release of the thumb allows the gases and liquid to gush out with explosive speed and force
Over the past hour, AVO has received numerous phone calls wondering whether Redoubt has erupted. All indications (seismic, radar, and satellite) are that it has not. Seismic unrest continues and the possibility of an eruption exists. AVO continues to monitor the situation 24/7.