Mw 7.2 quake, aftershocks rock Indonesian island

Magnitude 7.2 quake followed by dozens of strong aftershocks rattle the Indonesian island of Kepulauan Talaud

Earthquake Details

Magnitude: 7.2
Date-Time: Thursday, February 12, 2009 at 01:34:50 AM at epicenter
Location:  3.902°N, 126.400°E
Depth:  20 km (12.4 miles) set by location program
Region:  KEPULAUAN TALAUD, INDONESIA
Distances:

• 280 km (175 miles) SSE of General Santos, Mindanao, Philippines
• 320 km (195 miles) NNE of Manado, Sulawesi, Indonesia
• 1320 km (820 miles) SSE of MANILA, Philippines
• 2445 km (1520 miles) ENE of JAKARTA, Java, Indonesia

Location Uncertainty:  horizontal +/- 6.3 km (3.9 miles); depth fixed by location program
Source: USGS NEIC (WDCS-D)
USGS Event ID:  us2009cybb

Tectonic Summary [USGS]

The recent earthquake near Kepulauan Talaud, Indonesia of February 11, 2009 likely occurred as a result of reverse faulting on or near the plate-boundary system separating the Philippine Sea and Celebes Sea basins. Northeastern Indonesia is characterized by complex tectonics in which motions of numerous small plates are accommodating large-scale convergence between the Philippine Sea and Sunda plates. In the region of today’s earthquake, the Philippine Sea plate moves west-northwest with respect to the Sunda plate at a velocity of about 62 mm/year. Locally, arc-arc collision is occurring between the Sangihe and Halmahera micro plates, wedging between them the Molucca Sea micro plate, which subducts beneath both (i.e. to the east and west) and forms an inverted-U-shaped seismic zone. Seismicity within the Molucca Sea plate is active to depths of approximately 260 km to the east and 400 km to the west. The tectonic setting of this region is unique in that it is the only global example of an active arc-arc collision consuming an oceanic basin via subduction in two directions.

“The earthquake occurred approximately 30 km off the western coast of the Pulau Salebabu (Indonesia) in an area that has seen large earthquakes in the past. Since 1986, there have been two earthquakes with magnitude greater than 7 in this region.

Indonesia

Indonesia consists of more than 17,500 islands scattered over both sides of the equator, about 6,000 of which are inhabited.The five largest islands are Java, Sumatra, Kalimantan (the Indonesian side of Borneo), New Guinea (shared with Papua New Guinea) and Sulawesi.

Indonesian islands sit on the edges of the Australian, Eurasian and Pacific tectonic plates and are therefore subject to frequent earthquakes and volcanic eruptions. Indonesia is home to about 160 active volcanoes.

Related Links:

• Earthquakes [links page]

Earthquake Cluster Hits Yellowstone National Park

More than two dozen earthquakes magnitude 2.5 and larger strike Yellowstone National Park, Wyoming

FEWW Forecast: There could be as much as 37 percent more earthquakes in the United States in 2009;  some may occur in areas not prone to quakes, e.g., north, northeast, south and central U.S.

Magnitude 3.5 quake strikes  YELLOWSTONE NATIONAL PARK, WYOMING

Source: USGS

This Earthquake
Magnitude: 3.5

Date-Time:

• Wednesday, December 31, 2008 at 09:02:28 UTC
• Wednesday, December 31, 2008 at 02:02:28 AM at epicenter

Location: 44.523°N, 110.362°W
Depth: 0.4 km (~0.2 mile) (poorly constrained)
Region: YELLOWSTONE NATIONAL PARK, WYOMING
Distances:

• 61 km (38 miles) ESE (104°) from West Yellowstone, MT
• 64 km (40 miles) SSE (154°) from Gardiner, MT
• 64 km (40 miles) SSW (211°) from Cooke City-Silver Gate, MT
• 437 km (272 miles) NNE (16°) from Salt Lake City, UT

Location Uncertainty: horizontal +/- 0.5 km (0.3 miles); depth +/- 7.9 km (4.9 miles)
Source: University of Utah Seismograph Stations [via USGS]
Event ID: uu00002649

FEWW Team will provide a more definitive earthquake forecast for the US in 2009 once it’s had a chance to re-examine the data to confirm the preliminary analysis.

Redoubt’s ‘Phantom Unrest’ Could Lead to Eruption

Alaska Volcano Observatory

Information Statement – Friday, October 3, 2008 10:37 AM AKDT (10:37 UTC)

Redoubt Volcano

• Type of Volcano: Stratovolcano
• Coordinates: 60°29’7″ N 152°44’38” W
• Summit Elevation: 10197 ft (3108 m)
• Recent Eruptions:1902, 1966-68, and 1989-90
• Location: Western side of Cook Inlet, about 170 km southwest of Anchorage and 82 km east of Kenai, Alaska
• Current Volcano Alert Level: NORMAL

Current Aviation Color Code: GREEN

Annotated photo of Redoubt Volcano from the north, including features seen on 27 September, 2008.
Picture Date: September 27, 2008 – Image Creator: Kate Bull – Image courtesy of the AVO/ADGGS.
Full Size

What’s up at Redoubt?

Starting September 16, reports of strong hydrogen sulfide odor and loud noises coming from the direction of the volcano were reported. AVO observation flight on September 27 revealed:

• A number of fractures and circular openings in the upper Drift glacier for the first time.
• Scientist noted a strong hydrogen sulfide odor, but onboard instrumentation recorded no sulfur dioxide.
• Fumaroles on top of  domes formed in the 1968 and 1990 eruptions showed more vigorous steaming than the last observation in mid-August.
• AVO’s seismic network detected no abnormal earthquake activity, despite the earlier reports.

AVO believes Redoubt’s increased fumarolic activity and presence of sulfur odors do not suggest an imminent eruption, despite similar observations being made in the  months preceding the 1989-1990 eruption, when seismicity also increased significantly. AVO expects a similar strong increase in seismicity first before an eruption occurs.

Notes:

In the 1989-90 eruption lahar traveling down the Drift River partially inundated the Drift River Oil Terminal facility. Ash plumes produced during the same eruption affected international air traffic with traces of ashfall falling on Anchorage and nearby communities. (AVO)