Quake off Indonesia triggers tsunami alert


By the CNN Wire Staff

updated 7:54 AM EDT, Wed April 11, 2012


Jakarta, Indonesia (CNN) -- A massive earthquake struck off the coast of the Indonesian island of Sumatra on Wednesday afternoon, triggering a tsunami alert for the Indian Ocean.

The quake struck about 434 kilometers (270 miles) southwest of Banda Aceh, the capital of Indonesia's Aceh province, and had a magnitude of 8.6, the U.S. Geological Survey said. It took place at a depth of 23 kilometers (14 miles).

A second quake, magnitude 8.2, occurred off the west coast of Sumatra about two hours later, the USGS said.

Gary Gibson from the Seismology Research Center in Melbourne, Australia, said the location of the second quake reduces the possibility of a tsunami.

There were no immediate reports of destruction or deaths Wednesday.

Indonesian President Susilo Bambang Yudhoyono said on local television that there were no reports of casualties or damage in Aceh.

The Pacific Tsunami Warning Center issued a tsunami watch for the entire Indian Ocean, and the Indonesian Meteorology, Climatology and Geophysics Agency said it had put up a tsunami warning as well.

Sea level readings indicate a tsunami was generated, the warning center said. "It may already have been destructive along some coasts."

Read more here: http://www.cnn.com/2012/04/11/world/asia/indonesia-earthquake/index.html?hpt=hp_t1

From Michael Janitch's FB page:





From weather.com:

Experts said both quakes were geologically different than the one that spawned the 2004 tsunami, occurring horizontally, with the tectonic plates sliding against each other, creating more of a vibration in the water.

The other type of earthquake, a mega thrust, like the one that also hit off Japan last year, causes the seabed to heave and displaces water vertically, sending towering waves racing toward shores.

Roger Musson, seismologist at the British geological survey who has studied Sumatra's fault lines, said initially he'd been "fearing the worst."

"But as soon as I discovered what type of earthquake it was ... I felt a lot better."

The tremors were felt in neighboring Malaysia, where high-rise buildings shook. Singapore, Thailand, Bangladesh and India also were rattled.

But it was the streets of Aceh where real chaos broke out.

Patients poured out of hospitals, some with drips still attached to their arms. In some places, electricity was briefly cut.

Hours after the temblor, people were still standing outside their homes and offices, afraid to go back inside.


FYI, the approximate antipode for Indonesia is the northwest area of Brazil, bordering on French Guiana

Another "aftershock":

6.0
Date-Time

Wednesday, April 11, 2012 at 09:27:56 UTC
Wednesday, April 11, 2012 at 03:27:56 PM at epicenter
Time of Earthquake in other Time Zones

Location 1.281°N, 91.731°E
Depth 9.8 km (6.1 miles)
Region NORTH INDIAN OCEAN
Distances

616 km (383 miles) SW (221°) from Banda Aceh, Sumatra, Indonesia
1127 km (700 miles) W (260°) from KUALA LUMPUR, Malaysia

These were the two events reported today!! (Corrected from the initial 8.9M!?)



8.7 Mw - OFF W COAST OF NORTHERN SUMATRA

Preliminary Earthquake Report

Magnitude 8.7 Mw

Date-Time
• 11 Apr 2012 08:38:38 UTC
• 11 Apr 2012 14:38:38 near epicenter
• 11 Apr 2012 09:38:38 standard time in your timezone

Location 2.348N 93.072E

Depth 33 km

Distances
• 431 km (268 miles) SW (216 degrees) of Banda Aceh, Sumatra, Indonesia
• 962 km (598 miles) W (265 degrees) of KUALA LUMPUR, Malaysia

Location Uncertainty - Horizontal: 14.0 km; Vertical 2.8 km
Parameters Nph = 243; Dmin = 514.3 km; Rmss = 1.67 seconds; Gp = 36°
M-type = Mw; Version = 8
Event ID US c000905e


8.2 Mw - OFF W COAST OF NORTHERN SUMATRA

Preliminary Earthquake Report

Magnitude 8.2 Mw

Date-Time
• 11 Apr 2012 10:43:09 UTC
• 11 Apr 2012 16:43:09 near epicenter
• 11 Apr 2012 11:43:09 standard time in your timezone

Location 0.773N 92.452E

Depth 16 km

Distances
• 615 km (382 miles) SSW (211 degrees) of Banda Aceh, Sumatra, Indonesia
• 1061 km (659 miles) WSW (256 degrees) of KUALA LUMPUR, Malaysia

Location Uncertainty Horizontal: 14.2 km; Vertical 6.4 km
Parameters Nph = 101; Dmin = 573.3 km; Rmss = 0.95 seconds; Gp = 39°
M-type = Mw; Version = 7
Event ID - US c00090da


Busy looking into the data of Sun Spots for the past two days to see if there is a link....