Archived Updates

Anatahan Volcano Update for September 30
Submitted Wednesday, October 1 at 10:00 a.m. local Anatahan time  

For the past 24 hours, Anatahan volcanic seismicity has been low, at a level similar to that for the last month of so. There were no apparent eruption signals or precursory events. Tremor and seismic energy release are low.

Heavy rain on September 22-26 precluded visual observations of the crater, even though several USGS geologists are on the scene, attempting to recover and remeasure survey benchmarks installed in past years. A tropical depression formed over CNMI on September 22, and heavy rains from then through the 26th mobilized the May-July tephra deposits on steep slopes, resulting in impressive debris-flow seismic signatures on the ANAT station. Gashes in the landscape record en masse local failure of rain-saturated tephra.

On September 27, observers saw the east crater lake from a helicopter.  A distinct odor of sulfur dioxide was present, and blue fume was apparent. 

On September 29, geysering through the lake was seen, and odor of hydrogen sulfide was present in addition to that of sulfur dioxide.  On neither day were any new deposits or features obvious.

Anatahan Volcano Update for October 1
Submitted Thursday, October 2 at 12:00 a.m. local Anatahan time  

For the past 24 hours, Anatahan volcanic seismicity has been low, at a level similar to that for the last month of so. There were no apparent eruption signals or precursory events. Tremor and seismic energy release are low.

Anatahan Volcano Update for October 2
Submitted Friday, October 3 at 10:00 a.m. local Anatahan time  

For the past 24 hours, Anatahan volcanic seismicity has been low, at a level similar to that for the last month of so. There were no apparent eruption signals or precursory events. Tremor and seismic energy release are low.

Anatahan Volcano Update for October 3
Submitted Saturday, October 4 at 10:00 a.m. local Anatahan time  

For the past 24 hours, Anatahan volcanic seismicity has been low, at a level similar to that for the last month of so. There were no apparent eruption signals or precursory events. Tremor and seismic energy release are low.

Anatahan Volcano Update for October 4
Submitted Sunday, October 5 at 11:00 a.m. local Anatahan time  

For the past 24 hours, Anatahan volcanic seismicity has been low, at a level similar to that for the last month of so. There were no apparent eruption signals or precursory events. Tremor and seismic energy release are low.

Anatahan Volcano Update for October 5
Submitted Monday, October 6 at 10:00 a.m. local Anatahan time  

For the past 24 hours, Anatahan volcanic seismicity has been low, at a level similar to that for the last month of so. There were no apparent eruption signals or precursory events. Tremor and seismic energy release are low.

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