Thursday, 27 July, 2017

7.8-magnitude quake hits Alaska, tsunami alert issued

The quake struck in the ocean off Russia's Kamchatka The quake struck in the ocean off Russia's Kamchatka
Melinda Barton | 18 July, 2017, 04:49

A tsunami advisory is in effect for Alaska's Aleutian Islands after a 7.8 magnitude quake struck off Russia's Kamchatka Peninsula Monday evening.

Civil Defence says a major quake under the ocean near Russian Federation does not pose a tsunami threat to New Zealand.

The epicenter of the magnitude-7.7 quake was located about 123 miles (199 km) east-southeast of Nikol'skoye, Russia, according to the USGS.

Originally, the USGS estimated the quake as a 7.4 magnitude but quickly revised it to 7.7.

It sparked a tsunami warning from the Pacific Tsunami Warning Centre. Tsunami waves were possible for coasts within 186 miles of the natural disaster epicenter, officials said.

Tsunami waves, however, were unlikely to reach Kamchatka's eastern coast, some 500 km (310 miles) away. There was also no tsunami warning for the South Pacific.

Note that with a magnitude 9.0 quake, the probability of an aftershock with a magnitude exceeding 7.5 is not negligible.