Umboi

Photo of this volcano
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 5.589°S
  • 147.875°E

  • 1548 m
    5077 ft

  • 251060
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Bulletin Report: September 1985 (SEAN 10:09) Citation IconCite this Report


Seismicity; subsidence in flank thermal area

"Following damaging earthquakes and changes at a thermal area on Umboi Island during August, local people were concerned about possible volcanic activity. A brief visit was made to Umboi by R. W. Johnson (Bureau of Mineral Resources, Canberra) on 5 September. He reported no signs of imminent volcanic threat but recommended that an officer from Rabaul Volcano Observatory (RVO) visit Umboi for further investigations.

"On 12 September, inspection of the thermal area on the W flank of Talo volcano (on the W side of Umboi Island) indicated that no increase in temperature had occurred. However, local subsidence had taken place. This was probably due to strong shaking of the ground during the strongest earthquake on 19 August.

"Nine local earthquakes were recorded 11-14 September, two reportedly felt. These earthquakes are probably local to Umboi Island, but it is uncertain whether they are directly related to the volcano. Seismic records indicate that earthquakes were continuing at a low level in mid-September."

Information Contacts: J. Mori, RVO.

The Global Volcanism Program has no Weekly Reports available for Umboi.

Bulletin Reports - Index


Reports are organized chronologically and indexed below by Month/Year (Publication Volume:Number), and include a one-line summary. Click on the index link or scroll down to read the reports.

09/1985 (SEAN 10:09) Seismicity; subsidence in flank thermal area




Information is preliminary and subject to change. All times are local (unless otherwise noted)


September 1985 (SEAN 10:09) Citation IconCite this Report


Seismicity; subsidence in flank thermal area

"Following damaging earthquakes and changes at a thermal area on Umboi Island during August, local people were concerned about possible volcanic activity. A brief visit was made to Umboi by R. W. Johnson (Bureau of Mineral Resources, Canberra) on 5 September. He reported no signs of imminent volcanic threat but recommended that an officer from Rabaul Volcano Observatory (RVO) visit Umboi for further investigations.

"On 12 September, inspection of the thermal area on the W flank of Talo volcano (on the W side of Umboi Island) indicated that no increase in temperature had occurred. However, local subsidence had taken place. This was probably due to strong shaking of the ground during the strongest earthquake on 19 August.

"Nine local earthquakes were recorded 11-14 September, two reportedly felt. These earthquakes are probably local to Umboi Island, but it is uncertain whether they are directly related to the volcano. Seismic records indicate that earthquakes were continuing at a low level in mid-September."

Information Contacts: J. Mori, RVO.

The Global Volcanism Program is not aware of any Holocene eruptions from Umboi. If this volcano has had large eruptions (VEI >= 4) prior to 10,000 years ago, information might be found on the Umboi page in the LaMEVE (Large Magnitude Explosive Volcanic Eruptions) database, a part of the Volcano Global Risk Identification and Analysis Project (VOGRIPA).

This compilation of synonyms and subsidiary features may not be comprehensive. Features are organized into four major categories: Cones, Craters, Domes, and Thermal Features. Synonyms of features appear indented below the primary name. In some cases additional feature type, elevation, or location details are provided.

Photo Gallery


The small circular island at the top-center is Sakar, the NE-most of a chain of volcanic islands off the northern coast of Papua New Guinea. The 8 x 10 km wide island, seen in this Space Shuttle image with north to the upper left, is an incised stratovolcano with a summit crater lake. No historical eruptions are known from Sakar, but a pyroclastic cone on the southern flank of the volcano may be of Holocene age. The 50-km-wide island of Umboi, whose left side is cut by a large caldera breached to the NE, fills the center of the image.

NASA Space Shuttle image STS50-100-D, 1992 (http://eol.jsc.nasa.gov/).
See title for photo information.
The 50-km-long island of Umboi, the largest of the volcanic islands off the north coast of New Guinea, is seen in this Space Shuttle image with north to the upper right. A large 13 x 17 km caldera cuts the northern half of the island and is widely breached to the NE (top-center). Three youthful post-caldera cones with summit crater lakes (left-center) are visible rising above the smooth-surfaced caldera floor. The large eroded massif at the right-center is an older volcanic complex, as is the dissected northern tip of the island (upper left).

NASA Space Shuttle image STS50-99-748-47, 2000 (http://eol.jsc.nasa.gov/).
See title for photo information.

Smithsonian Sample Collections Database


There are no samples for Umboi in the Smithsonian's NMNH Department of Mineral Sciences Rock and Ore collection.

Affiliated Sites