Category Archives: sumatra

Earthquake Report: Sumatra!

There were two interesting earthquakes near the northern tip of the Island of Sumatra whilst I was off on a field trip with some HSU geology students. So, I think it prudent to review these earthquakes now. These earthquakes happened … Continue reading

Posted in earthquake, sumatra, Transform

Earthquake Anniversary: Sumatra-Andaman 2004 M 9.2 & 2005 M 8.6

On 26 December 2004 there was an earthquake with a magnitude of M 9.2 along the Sumatra-Andaman subduction zone (SASZ). This earthquake is the third largest earthquake ever recorded by modern seismometers and ruptured nearly 2,000 km of the megathrust … Continue reading

Posted in asia, earthquake, education, geology, HSU, Indian Ocean, plate tectonics, subduction, sumatra, tsunami

Earthquake Report: Java Sea!

Last night as I was finishing work for the day, I noticed an earthquake in the Java Sea, just north of western Java. Here is the USGS website for this M 6.6 earthquake. This earthquake is extensional and plots very … Continue reading

Posted in collision, earthquake, education, geology, HSU, Indian Ocean, Indonesia, plate tectonics, subduction, sumatra

Earthquake Report: Burma!

Well, there was an earthquake about 6 hours ago in Burma. This M 6.8 earthquake was rather deep, which is good for the residents of that area (the ground motions diminish with distance from the earthquake hypocenter). Here is the … Continue reading

Posted in asia, collision, education, geology, HSU, Indian Ocean, plate tectonics, sumatra

Earthquake Report: Sumatra!

We just had a M = 7.8 earthquake southwest of the Island of Sumatra, a volcanic arc formed from the subduction of the India-Australia plate beneath the Sunda plate (part of Eurasia). Here is the USGS website for this earthquake. … Continue reading

Posted in asia, College Redwoods, earthquake, education, geology, HSU, Indian Ocean, Indonesia, plate tectonics, strike-slip, subduction, sumatra, Transform

Earthquake Report: Nicobar Isles and Sumatra!

This past 24 hours include two large earthquakes in the region of the Sumatra-Andaman subduction zone offshore of Sumatra. Here is a map using the USGS online GIS interface. Here are the two large earthquakes posted on the USGS websites: … Continue reading

Posted in asia, College Redwoods, earthquake, education, geology, HSU, Indonesia, plate tectonics, strike-slip, subduction, sumatra, Transform

Plate Tectonics: 200 Ma

Gibbons and others (2015) have put together a suite of geologic data (e.g. ages of geologic units, fossils), plate motion data (geometry of plates and ocean ridge spreading rates), and plate tectonic data (initiation and cessation of subduction or collision, … Continue reading

Posted in alaska, asia, cascadia, College Redwoods, collision, education, europe, Extension, geology, gorda, HSU, humboldt, Indonesia, Japan, kinetic, mendocino, oregon, pacific, plate tectonics, San Andreas, strike-slip, subduction, sumatra, Transform

Andaman Sea Earthquake!

Today we had a small earthquake in the Andaman Sea, west of Thailand and east of the Andaman Isles (India). The Andaman Sea is a region of backarc spreading and connects the Sumatra fault (a (strike-slip) sliver fault that accommodates … Continue reading

Posted in asia, education, Extension, geology, HSU, Indonesia, plate tectonics, strike-slip, subduction, sumatra, Transform

Earthquake near Siberut, Indonesia: Sumatra Megathrust

Yesterday (I was busy getting a Mt. St. Helens field trip together, here is the link for that) we had an earthquake with a magnitude M = 6.1. While this is not a large earthquake, it is notable because this … Continue reading

Posted in Chemeketa Community College, College Redwoods, education, geology, humboldt, Indonesia, plate tectonics, subduction, sumatra

Tohoku-Oki Aftershocks Continue

The aftershocks continue offshore northeast Japan. The recent swarm appear to align along a northwesterly strike (trend). Here is the USGS web page for the earthquake from today. This is the USGS web page for the largest magnitude earthquakes in … Continue reading

Posted in Chemeketa Community College, education, geology, Japan, plate tectonics, subduction, sumatra, tsunami