Earthquakes
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Bizarro Earth

US: Earthquake Magnitude 4.0 - Arkansas

Image
© USGS
Date-Time:
Friday, February 18, 2011 at 04:59:50 UTC

Thursday, February 17, 2011 at 10:59:50 PM at epicenter

Time of Earthquake in other Time Zones

Location:
35.257°N, 92.370°W

Depth:
5.1 km (3.2 miles)

Region:
ARKANSAS

Distances:
4 km (2 miles) NNE (29°) from Greenbrier, AR

8 km (5 miles) SE (143°) from Twin Groves, AR

8 km (5 miles) SSW (203°) from Guy, AR

58 km (36 miles) N (357°) from Little Rock, AR

420 km (261 miles) SSW (207°) from St. Louis, MO

Bizarro Earth

USGS Watching Mount St. Helen's Volcano Following Earthquake Swarm

Image
© Unknown
The United States Geological Survey is watching the Mount St. Helen's volcano closely after a series of earthquakes struck on Monday. The area around Mount St. Helen's in Washington state has been experiencing minor earthquakes since an initial quake measuring 4.3 in magnitude struck around 10:35 a.m. local time, according to the USGS. Since that first quake, several smaller aftershocks were registered ranging between 1.0 and 2.8 in magnitude.

All of these earthquakes were centered in an area approximately five to six miles north of the Mount St. Helen's crater near the Johnston Ridge Observatory. The quakes were registered at depths between 1.7 and 3.7 miles. In total, at least 12 small earthquakes were registered in the area since the first quake on Monday.

This series of small earthquakes occurring in approximately the same location over a short period of time is known as an earthquake swarm. According to the Global Volcanic Earthquake Swarm Database earthquake swarms are especially common around volcanoes and are often reliable methods of predicting an eruption but the Alaska Volcano Observatory website offered that there may be no need for alarm. The AVO website explained that while earthquake swarms may offer information that a volcano is becoming restless, they are not necessarily indicators of a pending eruption. According to the AVO, "Most seismic swarms are not precursors to eruptions."

Attention

US: 4.3 Magnitude Earthquake Hits Near Mt. St. Helens

A 4.3 earthquake hit the Mt. St. Helens area about 10:35 a.m. Monday, followed by 30 aftershocks, according to a USGS seismologist.


USGS Seismologist Seth Moran told KGW the quake was centered near the Johnston Ridge Observatory, and registered on seismic devices as far away as Mt. Rainier and at Timberline Lodge.

Moran said the seismic event lasted about three to five seconds, and shaking from the quake lasted up to three minutes. He said there were at least 30 aftershocks.

USGS data on the 4.3quake

The 4.3 quake (pictured on the seismograph), originally rated as only a 3.3 magnitude event, happened at 10:35 a.m., about six miles north and northwest of the volcano and about three miles deep.

Bizarro Earth

Indonesia - Earthquake Magnitude 6.1 - Sulawesi

Sulawesi Quake_150211
© USGSEarthquake Location
Date-Time:
Tuesday, February 15, 2011 at 13:33:53 UTC

Tuesday, February 15, 2011 at 09:33:53 PM at epicenter

Time of Earthquake in other Time Zones

Location:
2.470°S, 121.541°E

Depth
20.6 km (12.8 miles)

Region
SULAWESI, INDONESIA

Distances
160 km (100 miles) ENE of Palopo, Sulawesi, Indonesia

200 km (125 miles) NNW of Kendari, Sulawesi, Indonesia

1500 km (930 miles) NW of DARWIN, Northern Territory, Australia

1680 km (1040 miles) ENE of JAKARTA, Java, Indonesia

Radar

US: Quakes hit Mt. St. Helens, rattle Portland area

Image
Portland, Oregon - Two earthquakes hit the Mount St. Helens area Monday morning, and one was strong enough to be felt in the Portland-Vancouver area.

KATU received many reports from viewers in the Portland area who said they felt the 10:35 a.m. temblor.

The initial quake measured 3.5 and was followed by a 2.5., but then the first quake was re-evaluated as a 4.3 - a fairly robust temblor. A 2.3 aftershock struck just before noon.

Quakes are now measured on a "magnitude scale" instead of the Richter Scale, according to KATU News Meteorologist Dave Salesky.

Bizarro Earth

Chile Feels Aftershocks of Last Year's Massive Temblor

Chilean Quake Aftermath
© Science/AAASLast year's huge earthquake raised Chile's coast. The quake is still sending aftershocks through the region.
With five earthquakes rattling the coast over the past four days, Chileans are still feeling the aftershocks of a huge earthquake that ruptured one year ago.

A magnitude 6.8 earthquake offshore of Bío-Bío, Chile, on Feb. 11 sent thousands running for higher ground, the Associated Press reported. That quake triggered at least two dozen aftershocks, including earthquakes of magnitudes 6.0, 5.8 and 5.6, according to the U.S. Geological Survey (USGS). The rumbling continued today with a magnitude 6.6 temblor underwater near Maule, Chile.

"Chile is an active place so we always have a lot of earthquakes going on," said Don Blakeman, a geophysicist with the USGS in Golden, Colo.

That seismic activity is created as one of the Earth's rocky plates dives under another one. Near Chile, the Nazca plate is thrust under the much larger South American plate at a rate of about 2 inches (6 centimeters) per year.

Friday's magnitude 6.8 quake is thought to be an aftershock from the devastating magnitude 8.8 earthquake that struck Concepcion, Chile, last year, said Michael Bevis, a geophysicist at Ohio State University, who has studied how the earthquake last year changed Chile's coast. [See images of Chile's raised coast.]

"That's a huge earthquake, so it's going to have more aftershocks that last longer," than other, smaller earthquakes, Bevis told OurAmazingPlanet.

Bizarro Earth

US: Earthquake Magnitude 4.3 - Mount St. Helen's Area

Image
© USGS
Date-Time:
Monday, February 14, 2011 at 18:35:25 UTC

Monday, February 14, 2011 at 10:35:25 AM at epicenter

Time of Earthquake in other Time Zones

Location:
46.279°N, 122.215°W

Depth:
5 km (3.1 miles) set by location program

Region:
MOUNT ST. HELENS AREA, WASHINGTON

Distances:
9 km (6 miles) NNW (343°) from Mount St. Helens Volcano, WA

31 km (20 miles) S (171°) from Morton, WA

35 km (22 miles) SE (143°) from Mossyrock, WA

59 km (37 miles) ENE (75°) from Longview, WA

78 km (48 miles) NNE (23°) from Vancouver, WA

Bizarro Earth

Germany: Earthquake Magnitude 4.2 - West of Frankfurt

Image
© USGS
Date-Time:
Monday, February 14, 2011 at 12:43:10 UTC

Monday, February 14, 2011 at 01:43:10 PM at epicenter

Location:
50.388°N, 7.881°E

Depth:
5 km (3.1 miles) set by location program

Region:
GERMANY

Distances:
65 km (40 miles) WNW of Frankfurt am Main, Germany
90 km (55 miles) SE of Cologne, Germany
130 km (80 miles) SSE of Dortmund, Germany
450 km (280 miles) WSW of BERLIN, Germany

Bizarro Earth

Morocco: Earthquake Magnitude 4.5 - Southeast of Beni Mellal

Image
© USGS
Date-Time:
Monday, February 14, 2011 at 06:02:55 UTC

Monday, February 14, 2011 at 06:02:55 AM at epicenter

Time of Earthquake in other Time Zones

Location:
31.976°N, 6.070°W

Depth:
9.9 km (6.2 miles) set by location program

Region:
MOROCCO

Distances:
55 km (35 miles) SE of Beni Mellal, Morocco

125 km (80 miles) SE of Khouribga, Morocco

160 km (100 miles) W of Er-Rachidia, Morocco

240 km (145 miles) SSE of RABAT, Morocco

Bizarro Earth

Earthquake Swarm Just Part of New Kilauea Activity

Hawaii Volcanoes National Park - Scientists at the Hawaiian Volcano Observatory on the Big Island of Hawaii are looking at a swarm of small earthquakes that shook Kilauea Volcano last week.

There were at least 42 earthquakes in the area within a 24 hour period that started Thursday. Geophysicists said while the temblors have diminished, they are another clue in what may come next at the world's most active volcano.

"Kilauea's summit has been extending, meaning that more magma is coming up to the summit than is going out to the east rift zone," said Jim Kauahikaua, the observatory's scientist in charge. That means there's move lava underground that's headed toward the actual Kilauea caldera, rather than the zone where most of the activity has been in the volcano's 28 year long eruption.

According to Kauahikaua, the extension of the crater has been going on for a few months.

"This extension of the summit is also reflected in the rise in lava in the Halemaumau vent," he said.

"All of them are indications that pressure is increasing in the magma chamber below the summit."