Okmok in the Aleutian Islands erupts

Okmok Caldera in Alaska's Aleutian Islands erupted today, sending an ash column to at least 30,000 feet. Very little news has been released about the eruption so far beyond this information about the eruption column and some bits about precursor seismicity. A number of flights to Unalaska Island were cancelled due to the eruption. I'll pass on more information when I get it.

Okmok is located near Dutch Harbor, Alaska and is a large shield volcano with two prominent calderas at the top. In fact, whenever I see pictures of the caldera, I am reminded of what Crater Lake (Oregon) might look without the water. These calderas formed ~12,000 and 2,050 years ago but most recent eruptions have been from scoria cones from within the caldera. The last eruption at Okmok was in 1997, a VEI 3, with the next previously eruption in 1986 (VEI 2). Now, before everyone gets excited because that makes ~10 years between the last three eruptions, the one prior to 1986 was in 1983. So much for patterns!

More like this

Sorry about the delay with updates, I am actually at a meeting filled with volcanologists (of all things), so updates might be a little sporadic. A lot of news today about Okmok erupting in the Aleutians. The Alaska Volcano Observatory had this to say: The eruption at Okmok continues based on …
Sally Sennert from the Smithsonian Institution sent me an email to say that this week's USGS/Smithsonian Institute Weekly Volcanic Report will be delayed due to the inclement weather in the Washington DC area. She can't connect with the server, so the report can't be updated on the Smithsonian…
Sorry about the brevity of this update, but I'm exhausted. From the Alaska Volcano Observatory (AVO): At this time, based on AVO analysis of satellite data, ash is continuing to erupt from a composite cinder and spatter cone called Cone D in the eastern portion of the 6-mile wide caldera or crater…
Tambora, Indonesia There are big eruptions, then there are big eruptions. On April 10, 1815, Tambora, a volcano in Indonesia, produced one of the largest eruptions in human history. This eruption produced what became known as the "year without a summer" after the volcanic aerosols from the eruption…