Blog Posts Tagged "subduction zones"

Four Essential Questions

At the National Science Teachers Association’s (NSTA) national meeting in San Francisco on Friday, I got to meet a few School of Rock Alumni.  Thanks for the tips on what to expect and bring. I felt compelled to attend because I’ve never had the opportunity to attend an NSTA meeting and it was in my local area.  Squeezing it in between packing and getting everything else in order for a 30 day absence was well worth it.  With thoughts of Japan in the aftermath of the earthquake and the threat of the tsunami on our coast, the buzz of teachable moments and relevance of understanding Earth sciences was in the air of the Moscone Center with 15,000 science teachers.

Incoming! Oblique Subduction at the Sunda Subduction Zone

The Indian and Australian Plates plow northeast into the Sumatra subduction zone, part of the larger Sunda subduction zone, at a speed of 45 mm/yr. The angle between the direction these two plates move relative to each other is not always at a right angle (90°) to the subduction zone itself--here it is about 50°. Sliding under the Sunda Plate at an angle is not easy, so several large strike-slip fault systems help to accommodate some of this movement. If you thought learning vectors in high school was pointless—think again. This is a perfect vector component problem!

Not So Fast! Types of earthquakes at the Sumatra Seismogenic Zone

Several different types of earthquakes and fault-slip events happen at the Sunda subduction zone and other subduction zones around the world. Typical earthquakes usually last a few seconds to a few minutes, if they have very large magnitude. But not all fault slip results in typical earthquakes.