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Dawson Strait Group

Photo of this volcano
  • Papua New Guinea
  • Melanesia and Australia
  • Volcanic field
  • 1350 CE
  • Country
  • Volcanic Region
  • Primary Volcano Type
  • Last Known Eruption
  • 9.62°S
  • 150.88°E

  • 500 m
    1640 ft

  • 253060
  • Latitude
  • Longitude

  • Summit
    Elevation

  • Volcano
    Number

Most Recent Bulletin Report: December 2000 (BGVN 25:12) Citation IconCite this Report

Occasional seismic swarms 1989-99; no eruptive activity

During August-October 2000 there were no reports of unusual volcanic activity occurring at Esa'ala (also called the Dawson Strait group). RVO had a 1960s-vintage seismic recorder at Esa'ala until 1994. Since then, maintenance and funding problems have meant it has neither functioned nor been replaced. Discussion with Professor Abe following a seismic survey in the area in the second part of 1999 revealed that he had seen continued seismicity at the Esa'ala base station.

The last notable seismic swarm at Esa'ala before the RVO instrument broke down was in November-December 1992. Another prior swarm of earthquakes took place in mid-December 1989 (BGVN 15:01). RVO maintains a part-time observer at Esa'ala who keeps track of felt earthquakes. He typically reports that no felt earthquakes have occurred.

General References. Davies, H.L., 1973, Fergusson Island, Papua New Guinea-1:250,000 Geological Series: Bur. Miner. Resour. Aust. explan. Notes, SC/56-5.

Smith, I.E.M., 1976, Peralkaline rhyolites from the D'Entrecasteaux Islands, Papua New Guinea, in Johnson, R.W., ed., Volcanism in Australasia: Elsevier, Amsterdam, p. 275-285.

Smith, I.E.M., 1981, Young volcanoes in eastern Papua in Johnson, R.W., ed., Cooke-Ravian Volume of Volcanological Papers: Geological Survey of Papua New Guinea Memoir 10, p. 257-265.

Information Contacts: Ima Itikarai, Rabaul Volcano Observatory (RVO), P.O. Box 386, Rabaul, Papua New Guinea.

The Global Volcanism Program has no Weekly Reports available for Dawson Strait Group.

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.

01/1990 (BGVN 15:01) Felt swarm of A- and B-type earthquakes; divers film submarine vents and hear booming and roaring

12/2000 (BGVN 25:12) Occasional seismic swarms 1989-99; no eruptive activity




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


January 1990 (BGVN 15:01) Citation IconCite this Report

Felt swarm of A- and B-type earthquakes; divers film submarine vents and hear booming and roaring

"A swarm of earthquakes took place in the Esa'Ala area in mid-December 1989. Earthquakes were felt with intensities MM III-V by villagers at Esa'Ala, Dobu Island, and on SE Fergusson Island at Oiau, Deidei, and Numa Numa. The local volcano observatory at Esa'Ala noted felt events on the 10th (26 events), 11th (12), 12th (6), and the 13th (3).

"Reports received at RVO on 11 and 13 December prompted a 5-day on-site inspection and local seismic recording by three RVO officers, 13-18 December. When local recording resumed at Esa'Ala Volcano Observatory (on the 13th), 30 sharp volcano-tectonic earthquakes (A-type with S-P

Table 1. Number of A- and B-type events recorded at the Esa 'Ala Observatory, 13-17 December 1989.

Date A-type B-type
13 Dec 1989 30 57
14 Dec 1989 25 55
15 Dec 1989 23 27
16 Dec 1989 12 16
17 Dec 1989 16 9

"The deployment of two portable seismographs at Numa Numa and Waiope Island, together with the seismograph at the Esa'Ala Volcano Observatory, allowed location of some of the larger earthquakes. Of the five earthquakes located, three occurred in the Dobu passage, another under Dobu Island, and the 5th between Dobu Island and Neumara Island (figure 1). These locations lie [near the outline] of an inferred submerged caldera.

Figure (see Caption) Figure 1. Map of the Dawson Strait Group area, showing volcanic vents, the volcano observatory (with permanent seismograph), sites of two portable seismographs deployed 13-18 December 1989, and the five earthquakes located during that period. Courtesy of RVO.

"The strongest earthquake caused minor landslides from 4-30-m cliffs of pyroclastic deposits along the N and E shores of Dobu Island, and one landslide inland, from a steep gulley on the E flank of Dobu. Ground cracks, 1-4 m inland and 0.5-2 cm wide, reported at Kenaie village on the NE side of Dobu Island were related to the collapse of marine cliffs parallel to their edges.

"Off the N coast of Dobu Island on the afternoon of the 11th, a team of professional divers filmed and photographed very turbulent springs (28°C) and degassing vents through sand holes up to 1 m in diameter, at a depth of 6 m of water. They also reported subcontinuous booming and roaring underwater sounds (at an estimated 30-40 db level).

"The December 1989 earthquake swarm was the first episode of unrest [in this area] since April 1969. At that time (1969), over a period of a few days, 5-7 shocks were felt daily, accompanied by noises. This prompted spontaneous evacuation of villagers on Dobu Island and around Oiau Volcano. Recording at the time was from one station only (ESA). On the basis of the S-P interval (1-1.4 seconds) and reports of earthquake intensities, the swarm was presumed to have originated from the Dobu Passage."

Information Contacts: I. Itikarai and P. de Saint-Ours, RVO.


December 2000 (BGVN 25:12) Citation IconCite this Report

Occasional seismic swarms 1989-99; no eruptive activity

During August-October 2000 there were no reports of unusual volcanic activity occurring at Esa'ala (also called the Dawson Strait group). RVO had a 1960s-vintage seismic recorder at Esa'ala until 1994. Since then, maintenance and funding problems have meant it has neither functioned nor been replaced. Discussion with Professor Abe following a seismic survey in the area in the second part of 1999 revealed that he had seen continued seismicity at the Esa'ala base station.

The last notable seismic swarm at Esa'ala before the RVO instrument broke down was in November-December 1992. Another prior swarm of earthquakes took place in mid-December 1989 (BGVN 15:01). RVO maintains a part-time observer at Esa'ala who keeps track of felt earthquakes. He typically reports that no felt earthquakes have occurred.

General References. Davies, H.L., 1973, Fergusson Island, Papua New Guinea-1:250,000 Geological Series: Bur. Miner. Resour. Aust. explan. Notes, SC/56-5.

Smith, I.E.M., 1976, Peralkaline rhyolites from the D'Entrecasteaux Islands, Papua New Guinea, in Johnson, R.W., ed., Volcanism in Australasia: Elsevier, Amsterdam, p. 275-285.

Smith, I.E.M., 1981, Young volcanoes in eastern Papua in Johnson, R.W., ed., Cooke-Ravian Volume of Volcanological Papers: Geological Survey of Papua New Guinea Memoir 10, p. 257-265.

Information Contacts: Ima Itikarai, Rabaul Volcano Observatory (RVO), P.O. Box 386, Rabaul, Papua New Guinea.

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.

Eruptive History

There is data available for 1 Holocene eruptive periods.

Start Date Stop Date Eruption Certainty VEI Evidence Activity Area or Unit
1350 (?) Unknown Confirmed   Hydration Rind Oiau
Deformation History

There is no Deformation History data available for Dawson Strait Group.

Emission History

There is no Emissions History data available for Dawson Strait Group.

Photo Gallery

The Dawson Straits, located between eastern Fergusson Island (upper left) and western Normanby Island (lower left) in the D'Entrecasteaux island group, contains a volcanic field with several young volcanic centers that produced rhyolitic obsidian flows. Mount Oiau lies along the narrow peninsula (left-center) forming the southernmost point on Fergusson Island. A large crater is visible on Dobu Island in this NASA Landsat image, south of Oiau and east of Normanby Island. Young volcanic rocks are also found on Sanaroa Island (upper right).

NASA Landsat7 image (worldwind.arc.nasa.gov)
See title for photo information.
GVP Map Holdings

The maps shown below have been scanned from the GVP map archives and include the volcano on this page. Clicking on the small images will load the full 300 dpi map. Very small-scale maps (such as world maps) are not included. The maps database originated over 30 years ago, but was only recently updated and connected to our main database. We welcome users to tell us if they see incorrect information or other problems with the maps; please use the Contact GVP link at the bottom of the page to send us email.

Title: Esa'Ala
Publisher: Natl Mapping Bureau, Royal Australian Survey Corps
Country: PNG
Year: 1987
Series: T601
Map Type: Topographic
Scale: 1:100,000
Map of Esa'Ala
Title: Sol-I Region, Topo of the
Publisher: USGS-CCOP/SOPAC S. Pacific Project
Country: Solomon Is
Year: 1983
Map Type: Bathymetric
Scale: 1:1,800,000
Map of Sol-I Region, Topo of the
Title: Papua New Guinea, Solomon Islands
Publisher: DMA & Defence Department, AIS, Melbourne,Australia
Country: PNG, Solomon Is
Year: 1981
Series: ONC
Map Type: Topographic
Scale: 1:1,000,000
Map of Papua New Guinea, Solomon Islands
Title: Duau
Publisher: Natl Mapping Bureau, Royal Australian Survey Corps
Country: PNG
Year: 1979
Series: T601
Map Type: Topographic
Scale: 1:100,000
Map of Duau
Title: Geology of Australia
Publisher: BMR, Geology & Geophysics, Dept Natural Resources
Country: Australia
Year: 1976
Map Type: Geology
Scale: 1:2,500,000
Map of Geology of Australia
Title: Fergusson Island
Publisher: BMR, Australia in coop with Geological Survey, PNG
Country: PNG
Year: 1972
Map Type: Geology
Scale: 1:250,000
Map of Fergusson Island
Smithsonian Sample Collections Database

The following 3 samples associated with this volcano can be found in the Smithsonian's NMNH Department of Mineral Sciences collections, and may be availble for research (contact the Rock and Ore Collections Manager). Catalog number links will open a window with more information.

Catalog Number Sample Description Lava Source Collection Date
NMNH 117455-33 Obsidian Oiau Crater --
NMNH 117455-34 Obsidian Oiau Crater --
NMNH 117455-35 Obsidian Oiau Crater --
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