Tsunami Warning Cancelled After Large Kermadec Quake

Kermadec quake on the Oturere volcano drum

“A robust one in the Kermadecs just hit this morning. Tidal swell expected.Seismic activity has certainly been on the increase.

http://riktindall.wordpress.com/tag/kermadecs/ snip – “This momentary alarm follows recent escalation of Fiji area 5+ quakes, that was already amidst a period of heightened seismic activity on the north and east Australian Plate. New Zealand geology is ultimately affected by this type of movement, as I began warning eleven days ago: 5.7 south-west Tonga Trench ridge quake shakes NZ. Then two days ago, it was already looking like a ‘more noticable’ /serious? seismic brewing, which GNS Science advise us not to see: Taupo 6.5 quake not good news 4 ChristChurch or NZ. Three days ago, I showed precisely where to watch for any imminent local bad shakes again: Next ChristChurch 6+ quake (is just starting to trend below the critical ten gigajoule Quake Energy release line again – WARNING! …)

One point of interest is the unpredictability of it all. Per Teara: “The historical record in New Zealand is rather short to be accepted as an accurate guide to the distribution of future epicentres.”

The NE Australian plate causing all the problems, and the size of New Zealand compared to the size of the edge of that plate, can be seen here: http://whatonearth.olehnielsen.dk/plates/australian.asp”  (Sent in by Rocknroll)

NZ is almost lost in the divide between the plates

The large 7.6 quake sparked a tsunami warning for New Zealand but this was later replaced by alerts for high tides and abnormal currents for the next 24 hours. More here

A smaller 6.4 Kermadec quake struck on 19 April and was was widely felt from Auckland to as far south as Dunedin. More here

From Wikipedia

The Kermadec trench is one of Earth’s deepest oceanic trenches, reaching a depth of 10,047 metres (32,963 ft). Formed by the subduction of the Pacific Plate under the  Indo-Australian Plate, it runs over a thousand kilometres parallel with and to the east of the Kermadec Ridge and island arc, from near the northeastern tip of New Zealand’s North Island to the trench’s junction with the Louisville seamount chain northeast of Monowai Seamount. The Tonga Trench marks the continuation of subduction beyond this point. Subduction south of the Kermadec trench is marked by the shallower Hikurangi Trench.

Kermadec trench is specially noted by its very abrupt slope.