Great Earthquake in Kuril Islands

A great (over magnitude eight) earthquake struck at a shallow depth to the east of the Kuril Islands, north of Japan, this afternoon.

The magnitude 8.2 quake struck at a depth of 10 km at 5:23 p.m. New Zealand Daylight Time on Saturday 13th January 2007, according to data released by the US Geological Survey (USGS). The trace from the earthquake showed strongly on the Geonet website’s seismographs in New Zealand 12 minutes later at 5:35 p.m.

The earthquake, which has been revised upward from magnitude 7.7 to 8.2 by the USGS, struck 95 km ESE of the magnitude 8.3 quake of November 15, 2006.

The Pacific Tsunami Warning Centre (PTWC) initially estimated the quake at magnitude 8.4 but, after further analysis, has settled on magnitude 8.2. A tsunami warning was issued for Russia, Japan and Marcus Island shortly after the quake.

The first sea-level gauge data was reported in PTWC’s bulletin at 7:44 this evening, stating that a 10 cm wave had been reported at Hanasaki Hokkaido, Japan 1 hour 42 minutes after the earthquake. However, whilst sea-level readings indicated that a tsunami was generated, further information is awaited. The PTWC point out that the initial wave may not be the largest.

An ADVISORY ONLY is in place for most Pacific locations, with a tsunami watch issued for Midway, Guam, The Philippines, Hawaii and similar locations.

A magnitude 8.3 quake which struck the Kuril Islands on November 15th last year, caused a tsunami which was barely noticed in New Zealand. The initial wave took just over 14 hours to travel to New Zealand’s shores where it caused waves up to half a metre high on the South Island’s east coast. It wasn’t until 40-odd hours later that slightly larger waves were reported by sea-level gauges in New Zealand after the tsunami waves had been reflected off undersea structures.

Whilst the November tsunami was barely noticed in New Zealand, it caused isolated damage in northern California and Hawaii in the United States of America, where the waves were higher.

One Response to “Great Earthquake in Kuril Islands”

  1. Chris says:

    heck, only 10km’s deep – that’s stuff all. I was wondering what the seismic data on geonet was – you’ve pretty much answered that for me.

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