When was the last time Mt. Fuji erupted?

Mount Fuji's Shadow

Mount Fuji is famous for it’s perfectly symmetrical cone. This photograph shows the shadow of Fuji projected of the adjacent countryside at sunrise. This photograph, taken in May of 1962, is copyrighted by Robert Decker.

Mt. Fuji is a beautiful example of a stratovolcano, and is almost a perfect symmetric cone (at least when viewed from far away).  It is mostly basalt, which is a little bit unusual for stratovolcanoes as most stratovolcanoes are constructed of andesite or dacite compositions.   That it is a stratovolcano means that it is composed of layers of both lava and ash.  The fact that it is such a beautiful cone probably indicates that it hasn’t recently suffered a big eruption.

“Volcanoes of the World” by Tom Simkin and Lee Seibert lists 63 eruptions of Mt. Fuji since about 9000 years ago.  Obviously most of these have been determined by using carbon-14 dating rather than accounts by witnesses.  However, the most recent 22 eruptions are listed as having been recorded by people. The most recent eruption was probably the Hōei eruption which started on December 16, 1707 and ended about January 1, 1708.  The eruption formed a new crater and a second peak (named Hōei-zan) halfway down its side. Fuji spewed cinders and ash which fell like rain in Izu, Kai, Sagami, and Musashi. Since then, there have been no signs of an eruption.

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Rise and fall of underwater volcano revealed by sonar

More great stuff from the researchers studying Monowai and undersea volcanism near Tonga.  In a period of less than a month, researchers noted “huge changes” in the height of the volcano – according to a recent article in Nature Geoscience  (Watts, A.B., Peirce, C., Grevemeyer, I., Paulatto, M., Stratford, W., Bassett, D., Hunter, J., Kalnins, L., de Ronde, C. & Lamarche, G. 2012. Rapid rates of growth and collapse at Monowai submarine volcano, Kermadec arc. Nature Geoscience)  

3d image of MonowaiThis research into the Monowai volcano provides a fascinating insight into the little-known world of submarine geology.  You can read more and view a 360 degree model of the changes at this webpage from BBC News

This is the same group that showed us an entire chain of mountains marching to subduction at the Pacific / Indo-Australian plate boundary in 2011.   You can read that full article here.

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Fantastic Pictures from Bezymianny

Culmination of the volcano eruption at 21:40 UTC on March 08, 2012. Photo by Yu. Demyanchuk.

Dr. Olga Girina from KVERT sent a message with a link to this excellent website with current pictures from Bezymianny.   Very very cool stuff!

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Volcanoes Vex Air Force Base Relocation

The proposal to relocate the 18th Aggressor Squadron’s 21 F-16s from Eielson, located 25 miles southeast of Fairbanks, to Joint Base Elmendorf-Richardson in Anchorage is intended to save money. It’s part of an $8.7 billion dollar cut to the Air Force budget. Alaska is one of 33 states with bases affected by proposed cuts.

Alaska’s congressional delegation and Gov. Sean Parnell expressed that concern in a letter sent Wednesday to the Air Force’s secretary and chief of staff stating that “When volcanoes near Anchorage erupt, the air space can close.  While the Air Force has measures in place to respond to a volcanic eruption, the cost of relocating the fighter planes to another base would be increased if the F-16s were at Elmendorf-Richardson.”

Read more @: Fairbanks Daily News-Miner – Alaska delegation Parnell say Eielson move poses volcano risk

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So…. the issue here as I’m reading it is moving from 25 miles SE of Fairbanks to Anchorage where there is a greater risk of ash.

Well…. let’s take a closer look at the situation…

Here’s a map of Alaska near Anchorage from the Alaka Volcano Observatory.

Volcanoes near Anchorage

Upwind from Anchorage we have Spurr

Spurr Ash from the 1992 Eruption from the Michigan Technological University EOS Volcanology

Spurr Ash from the 1992 Eruption from the Michigan Technological University EOS Volcanology

and Redoubt

Redoubt Ash Fall

Next to Fairbanks we have (also from AVO):

Interior Alaska Volcano Map Courtesy of the Alaska Volcano Observatory

A tuff ring and a dome.

My humble opinion is … don’t move the planes.    Just sayin’

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Earthquake Swarm Rumbles in Hawaii

Current Seismic Activity

Current Seismic Activity

The U.S. Geological Survey’s Hawaiian Volcano Observatory reports the Kaoiki seismic swarm continues about three miles Northwest of Halemaumau Crater with increased activity overnight with two magnitude 4+ earthquakes Friday (Feb 24).

As of 7:15 a.m. Friday 78 earthquakes were recorded in the previous 24 hours with 74 of these were related to the earthquake swarm, two were in the upper East rift zone and two were on the South flank faults.

Click the map for a continuously updated map of earthquakes in Hawaii

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February 15-21, 2012

Volcanoes with reported activity include:

Cleveland, Chuginadak Island | Kanaga, Andreanof Islands | Reventador, Ecuador | Tinakula, Santa Cruz Islands (SW Pacific) | Tungurahua, Ecuador | Turrialba, Costa Rica | Bezymianny, Central Kamchatka (Russia) | Hierro, Canary Islands (Spain) | Karymsky, Eastern Kamchatka (Russia) | Kilauea, Hawaii (USA) | Kizimen, Eastern Kamchatka (Russia) | Popocatépetl, México | Puyehue-Cordón Caulle, Central Chile | Sakura-jima, Kyushu |  Shiveluch, Central Kamchatka (Russia)

As always, you can view loads of additional background information at Volcano World (http://volcano.oregonstate.edu) and detailed activity reports at the Smithsonian/USGS Global Volcanism Program.  (http://www.volcano.si.edu/reports/usgs/)

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The IAVCEI 2012 Calendar

Every year, the IAVCEI (the International Association of Volcanology and Chemistry of the Earth’s Interior for the newbs…) puts out the call for the most amazing volcano pictures (I’m sure glad I’m not on the decision making committee…) and this years calendar is very cool.

The 2012 IAVCEI Volcano Calendar is now available at:

Calendars.com
http://www.calendars.com/Weather/Volcanoes-2012-Wall-Calendar/prod201200004736/?categoryId=cat00387

OR, you can also buy the calendars directly from the publisher at:
http://www.browntrout.com/calendars/product.asp?MGID=-1&IID=11751

I’d suggest buying one – If this one doesn’t sell well…, they might do a “Men of Geology” calendar next year…

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