Significant Quakes Strike Both Sides of Pacific; NZ Volcanoes Awaken

DET

M7.0 earthquake strikes Vanuatu followed by M6.6 at Northern East Pacific Rise

M7.0 earthquake occurred beneath the island of Melampa in the Vanuatu island chain of the southwest Pacific Ocean as a result of thrust faulting on or near the boundary between the Australia and Pacific plates, USGS/EHP reported.

EQ Details

Magnitude: 7.0Mw [1km SE of Norsup, Vanuatu]
Location: 16.074°S, 167.393°E; depth=27.2 km (16.9 mi)
Time: 2016-04-28 19:33:24 (UTC)
Distances:

1.0km (0.6 mi) SE of Norsup, Vanuatu
64.0km (39.8 mi) SSE of Luganville, Vanuatu
208.0km (129.2 mi) NNW of Port-Vila, Vanuatu
536.0km (333.1 mi) N of We, New Caledonia

Magnitude: 6.6Mw [Northern East Pacific Rise]
Location: 10.271°N, 103.715°W; depth=10.0 km (6.2 mi)
Time: 2016-04-29 01:33:38 (UTC)
Distances:

• 602.0 km (374.1 mi) E of Clipperton Island, France
• 838.0 km (520.7 mi) SSW of Acapulco de Juarez, Mexico
• 838.0 km (520.7 mi) SSW of Tecpan de Galeana, Mexico
• 844.0 km (524.4 mi) SSW of Petatlan, Mexico
• 1,126.0 km (699.7 mi) SSW of Mexico City, Mexico

NO major tsunami threats generated by the two quakes.

Two NZ Volcanoes Show Signs of Unrest

Mt Ruapehu

A volcanic earthquake swarm has been reported at Mt Ruapehu. The seismicity began on April 26. The Crater Lake temperature, which has been rising since October 2015,  has now reached 40°C (from 25°C in mid-April). Mt Ruapehu remains at Volcanic Alert Level 1 (Minor volcanic unrest), Geonet reported.

White Island

A minor eruption occurred at White Island (Whaakari) at about 11:00 pm on Wednesday, 27 April 2016. Moderately elevated seismic activity is occurring, said Geonet. Additionally:

• Water level in the Crater Lake has fallen by 2m in the last 2 weeks.
• Lake temperature has increased by 2°C, to 58°C, since February.
• SO2 output ranging from 90 to 480 tons per day reported over the last 5 weeks, but said to be typical values for White Island.

“A dark-green ash deposit from the eruption covers at least 80% of the floor of Main Crater, and up the sides of the crater wall on both the north and south sides. At a distance of 500 m from the eruption site the ash deposit is about 5 mm thick. The green colour is due to minerals on the ash.”

Alert Level was initially raised to Level 3 (Minor Volcanic Eruption) and the Aviation Color Code to Orange. The Alert Level was lowered to 2 from 3 on Thursday.