Anatahan Volcano Update
Anatahan Volcano Update for May 4, 2004
Submitted Tuesday, May 4, 2004 at 0930 local Anatahan time
On April 24, a moderate eruption began producing steam and ash to ~2,000
ft (600 m) at Anatahan. A "cow-pie"-shaped dome extruded a day or two
later. On April 28, the seismicity peaked at a high for the year, the
dome increased in size at about that time and explosions apparently
increased in size. The activity and seismicity level then slowly
decreased about 25 percent over five days until the night of May 3-4
CNMI time. At that time the seismicity
dropped off suddenly but smoothly by about 50 percent and then began
recovering slowly. Small explosions presumably still occur every minute
or so, and steam and ash are still rising to a few thousand feet. 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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