Magnitude 5.7 Earthquake - Christchurch, New Zealand

[Astronuc]

the USGS/NEIC have one station within NZ, in Wellington as part of its WWSN the next closest ones are more than 1000km away

It would seem they need an array in Canterbury. NZ seems to have a good network there.

 

[davenn]

It would seem they need an array in Canterbury. NZ seems to have a good network there.

you may already be aware of this ??
...
http://earthquake.usgs.gov/monitoring/gsn/

that gives the locations and operational status for the GSN, Global Seismic Network, formerly the WWSSN (World Wide Standard Seismic Network)

Once upon a time they were all running the Sprengnether long period horizontal seismometer
http://americanhistory.si.edu/collections/search/object/nmah_1445876

I ran one from home for most of the 1990's, it was a spare from the Otago University Geology Dept
where I did my geol. studies

They were a solid beast weighing around 80 lbs .. triangular shaped base about 1.5 ft per side
around 40lbs of the weight was in that central vertical cylinder of brass. the whole thing had a cover
over it with a little window to observe the arm centring pointer that you can see in the centre of the brass mass ... a really nice instrument

here's a link to many of the seismograms of the stations around the world
They update roughly every 30 mins

http://earthquake.usgs.gov/monitoring/operations/heliplots_gsn.php Dave

PS ... you may well be coming to realize over recent years, that this subject is a real hobby horse of mine

 

[Astronuc]

M5.7 - 229km SSE of L'Esperance Rock, New Zealand
http://earthquake.usgs.gov/earthquakes/eventpage/us10004tsd#general_region

Somewhere along the Kermadec Trench

 

[StevieTNZ]

As if Christchurch has had enough http://www.stuff.co.nz/national/86758316/christchurch-shaken-by-severe-earthquake

Geonet reported the 5.7 magnitude being centred 20 kilometres south-east of Culverden at a depth of 7km.