Sumatra Earthquake September 30, 3009 Recorded at Keele

 Earthquakes  3 Responses »
Sep 302009
 

Southern Sumatra Earthquake Magnitude 7.6, September 30, 3009 Recorded at Keele University, UK.
20090930 Sumatra Waveform
20090930 Sumatra and 20090929 Samoa Earthquakes
20090930 Sumatra Travel time
20090930 Sumatra to Keele path

So, large earthquakes are like buses. You wait months for one to come along and then two arrive within hours of each other. I used to think that one event couldn’t trigger another at this sort of range but it does look a bit more than coincidence.

Note that this earthquake was deeper than the Samoan one (about 80km down) so the surface waves are much less pronounced. Also, as this event is a bit closer to Keele so we are not in the core shadow and can see the P, PP, S & SS arrivals.

The Keele seismic station is part of the UK Seismology for Schools programme.

 Posted by at 12:58  Tagged with:

Samoa Earthquake September 29, 2009 Recorded at Keele

 Earthquakes, tsunami  7 Responses »
Sep 302009
 

Samoa Earthquake September 29, 2009, M 8.0 recorded at Keele University, UK.
20090929 Samoa
20090929 samoa earthquake
20090929 samoa earthquake travel time curve
20090929 samoa earthquake path to keele

This earthquake caused a tsunami which hit the local islands causing at least 65 deaths in Samoa and at least 20 deaths in American Samoa according to the BBC.

It is unusual in that although it occurs close to the trench where the Pacific Plate is subducted beneath the Australian Plate, the faulting mechanism has been determined as being a normal fault rather than a thrust.

Note that as Keele is 15665km as the earthquake travels from the epicentre the first arrival reaching Keele is actually PP, rather than the direct P-wave which is intercepted by the Earth’s core.

The Keele seismic station is part of the UK Seismology for Schools programme.

 Posted by at 07:18  Tagged with: ,
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