Showing posts with label 19 June 2012. Show all posts
Showing posts with label 19 June 2012. Show all posts

21 June 2012

197. Post-mortem of the Moe Quake

The news keep on reporting about a single injured person who was unlucky enough to be standing on a ladder close to the epicentre, but beyond that it seems like no-one else suffered any injuries serious enough to warrant medical attention.

Property damages are a different story though, but the news are having a field day with it, so no point in me repeating what they are saying. My only comment is that the Gippsland/La Trobe Valley area has been hit hard lately, first by floods, storms and now an earthquake -- in addition to recent job losses and uncertainties.

Anyway, science.

www.ga.gov.au has a nice page with technical information about the earthquake:
http://www.ga.gov.au/earthquakes/getQuakeDetails.do?quakeId=3226344

There are several seismograms available from different stations around the country (am I the only chemist who looks at them wanting to apply a FFT?)

Victoria


ACT

Northern QLD

The shape varies with the distance from the earthquake, which I guess tallies with different types of waves travelling at different speeds.

For those of us who are reasonably new to this area, the USGS has a historical earthquake map over Melbourne and the Gippsland/La Trobe valley area.

Here's seismicity in Australia as a whole, and it shows that SE Victoria is no stranger to phenomenon:

http://www.quakes.uq.edu.au/html/quake_info/OZ_QLD_info.html#6

Big earthquakes are a different matter though: http://earthquake.usgs.gov/earthquakes/world/australia/seismicity.php

Only a handful of earthquakes show up on this map, and they are  in WA and NT.

Here's a map with the number of large earthquakes per year (5 and above) -- and Melbourne is by no means the worst hit by the Top 5 cities in Australia
http://earthquake.usgs.gov/earthquakes/world/australia/density.php

Finally, here's a map with the 'earthquake hazard' estimates for different regions of Australia:
http://earthquake.usgs.gov/earthquakes/world/australia/gshap.php

It seems like SE Tassie is the safest, inhabited area. SW WA is the least safe one, but is still nothing compared to PNG and Indonesia and other countries on plate boundaries.

Here's a full paper on seismic hazards in Australia, which contains a nice map with past earthquakes indicated on it: http://www.sciencedirect.com/science/article/pii/S0040195104002185
I'm loading the picture from the publisher's website which is probably the lesser of two evils.