Anatahan Volcano Update
Anatahan Volcano Update for May 2, 2004
Submitted Sunday, May 2, 2004 at 1200 local Anatahan time
Anatahan seismic activity increased abruptly early April 24 (UT) to a
high
level unseen since summer 2003, and a moderate eruption began producing
steam and ash to ~2,000 ft (600 m) at that time. An overflight on the
24th
reported fresh lava within the inner crater. The seismicity level
increased further on the 24th and 25th. On April 26, a "cow-pie"-shaped
dome was observed within the inner crater. Early on April 28, the
seismicity level increased further to a new high around mid-day (UT) and
the dome likely increased in size about that time. The average
seismicity level has since decreased somewhat over the last 3 1/2 days. The nature of the
seismicity indicates that regular explosions of
yellow-brown steam and ash are occurring every 1/2 to 2 minutes, as
observed on the 26th, and a plume is still rising to less than 6,000 ft
(2,000 m). The eruption could become more explosive at any time with
little or no warning.
The Emergency Management Office, Office of the Governor, CNMI, has
placed Anatahan Island off-limits until further notice and concludes
that, although the volcano is not currently dangerous to most aircraft
within the CNMI airspace, conditions may change rapidly, and aircraft
should pass upwind of Anatahan or >30 km downwind from the island and
exercise due
caution within 30-50 km of Anatahan.
Contact persons:
Juan Takai Camacho, Geophysical Seismic Technician, EMO Saipan; tel:
(670) 322-9528, fax: (670) 322-7743, email: juantcamacho@hotmail.com
Ramon Chong, Geophysical Instrument Specialist, EMO Saipan; tel: (670)
322-9528, fax: (670) 322-7743, email: rcchongemo@hotmail.com
Frank Trusdell, Geologist, USGS; tel: (808) 967-8812, fax: (808) 967-8890,
email: trusdell@usgs.gov
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