SI/USGS Weekly Volcano Activity Report for 4/29-5/5/2009

i think its time for other update on yellowstone

look at this 242 earthquakes in April

LLOWSTONE VOLCANO (CAVW#1205-01-)
44.43°N 110.67°W, Summit Elevation 9203 ft (2805 m)
Volcano Alert Level: NORMAL
Aviation Color Code: GREEN

April 2009 Yellowstone Seismicity Summary

During the month of April 2009, 242 earthquakes were located in the Yellowstone region. The largest event was a magnitude 2.7 on April 28 at 7:14 PM MDT, located about 6 miles north northeast of Old Faithful, YNP. A second M 2.7 was part of a swarm detailed below. There were three earthquake swarms during the month of April. The first, located 4 miles northwest of West Yellowstone, included 62 events spanning April 13-18 with magnitudes ranging from 1.3 to -0.6. The second, located 7 miles northwest of West Yellowstone, included 111 events from April 17-24 with magnitudes 2.3 to -0.8. The third swarm, located 11 miles northeast of Old Faithful, included 19 events all occurring on April 29th with magnitudes ranging from 2.7 to 0.5.

the weekly report is great, but always there is something that (to me anyway) does not aquite fit. I can see why clevland is there, even though the 'ongoing activity' is actually 'no activity' - because of the change in alert level. But i do not understand why this is in the report:

FERNANDINA Galápagos Islands 0.37°S, 91.55°W; summit elev. 1476 m

According to a news article, the eruption of Fernandina that began sometime between 2200 on 10 April and 0030 on 11 April continued after about 20 days. Variable activity included steam-and-gas emissions and lava flows.

...how is this 'new' activity?

Interesting article about Oldoinyo Lengai going to be in this months journal "Nature". You can read more about it here http://www.sciencedaily.com/releases/2009/05/090506144317.htm

David - Funny you mention Yellowstone. Last week when I went to the talk by Dr. Lowenstern, scientist-in-charge at YVO, he was mentioning that seisimicity had been low at Yellowstone overall for 2008, but then made up for it during the late 2008-early 2009 swarm that got us all excited. He did mention that during the swarm, there was a "spasmodic tremor" near Mary Lake that they haven't seen since 1/4/2009... until April 28 where there were six 2.5M EQs in 45 minutes. The general feeling now is that the Dec-Jan swarm was triggered by dilation and fluid flow under the park that triggered a bunch of tectonic quakes afterward.

Peter K - Yeah, I was puzzled by the Fernandina "update" as well. I guess they're just trying to catch up with older news.

Simon - Saw that article ... now I just need to digest it!

Nurfika Osman
Anak Krakatau Volcano Alert Raised

Indonesia has raised the warning level for Mount Anak Krakatau in the Sunda Strait to one level below its top alert, as the volcano becomes increasingly active and spews ash, geologists said on Thursday.

Officials were also closely monitoring another volcano, Mount Kerinci in West Sumatra, which has become more active in the past week.

%u201C[Anak Krakatau] poses a high threat because the eruptions have started spreading,%u201D said Surono, the head of the Volcanology and Geological Disaster Mitigation Center (PVMBG).

He said the volcano has been spewing molten lava up to 1,000 meters into the air this week.

%u201CThis is very dangerous, so we%u2019ve warned local residents and climbers to stay away from the volcano,%u201D he said.

Anton S. Tripanbudi, an observer at the Krakatau monitoring post in Pasauran, Banten, said that people have been warned against going anywhere within three kilometers of the mountain.

%u201CWhen the status was still [at the warning level], they were told to maintain a distance of just one kilometer,%u201D he said.

Anton said that in the 24-hour period leading up to Wednesday at noon, the monitoring facility recorded 55 eruptions, 51 earthquakes and five tremors. But local residents still went about their daily routines, he said.

%u201CThe volcano spewed hot volcanic rocks and ash 79 times during that period,%u201D he said, adding that the eruptions could be heard in Pandeglang, a town some 100 kilometers inland.

Anak Krakatau started emerging from the undersea caldera of what was known as Mount Krakatau in the late 1920s. Krakatau exploded in 1883 in one of the worst eruptions in modern history, blanketing the sky with ash for weeks and causing huge tidal waves that swept the coasts of Java and Sumatra on both sides of the Sunda Strait, killing an estimated 36,000 people.

looks like Krakatau Volcano could be a big one

looks like Krakatau Volcano could be a big one

The Halemaʻumaʻu vent on Kilauea is even brighter this morning then any of the last few days. Is lava getting closer to the surface? Hopefully HVO will put a time lapse infared loop together. There is a infared camera next to this one:

Halemaʻumaʻu overlook vent cam

http://hvo.wr.usgs.gov/cams/HMcam/

Hi, another thing about the weekly reports is the lack of info on Japanese volcanoes. Unfortunately they keep some of their juicy news only in Japanese! For example there was a recent report (which I have posted) of the crater lake of Shinmoedake turning brown from its usual colour of cobalt blue. No change in "activity" or seismicity though - any ideas why? Just a geochemical change?
Keep up the excellent work!!