Aotearoa Earthquake and Volcano Forecast Service

Aotearoa Summary. 24 May 2021 - 30 May 2021

Click to Enlarge

Weak solar shocks arrived 27 May but weren't strong enough to drive quakes and eruptions.
Sunspot AR2824 did drive a significant jetstream shift and a big storm into the Tasman Sea.
A C9 long duration flare and high energy proton storm on 29 May is probably the cause of the sudden power up of the Tasman Sea storm, catching weather forecasters by surprise.
The 26 May supermoon never had any effect on quakes without much solar wind.
The biggest local quake during the summary period was at least in a high risk location but too late to be a timing success.
Good riddance to the supermoon, it just adds another layer of complexity to an already cluttered solar data set and a forecast headache.
A coronal mass ejection is due 31 May and may create quakes.
24 May.
Christchurch/Avon Estuary 3.4 11.49am
30 May.
Waipukurau 4.2 5.55pm

Update. 27 May 10.00am
A mild solar shock has arrived this morning. Moderate geomagnetic storming is underway.
Local quakes may pickup today and become lunar modulated to low tide.
East Coast North Island is higher risk.
Low tide Porangahau = 11.40am

Update. 26 May 11.10pm
Local quakes are quiet on 26 May.
Background tremor is high on the Volcanic Plateau and Kermadec Ridge.
Signature North Island quake location Porangahau had several small quake swarms today.
Fortunately the expected arrival of a minor solar shock hasn't happened so quakes are unlikely, despite high tremor and a modulating supermoon.
The small shocks from sunspot AR2824 on 22 May have probably missed Earth or less likely are late arriving.
Other spaceweather forecasters, NASA etc. have made forecasts for a solar shock tonight, a day later than the forecast from this service.
They may yet be correct and a late shock arrives but usually our timing is better than theirs....time will tell.
Ionospheric heating and radio blackouts have been underway for several days from the high X-rays from sunspot AR2824 so the sunspot may yet drive a quake even if the solar shock misses Earth.
The forecast period is extended to 27 May.
Mag 6 is unlikely without a solar shock.

Update. 26 May 12.00am.
Local and Pacific quakes were quiet on 25 May.
Solar wind was quiet ahead of a mild solar shock due as this update is posted.
The 26 May 11.15pm supermoon eclipse may modulate quake magnitude upwards.
The forecast period is extended to 26 May.
Masterton, Eketahuna, Castlepoint are raised to Mag 5 risk.
Upper Rakaia River, Lord River, Upper Whitcombe River are added to Mag 4 risk locations.
Possibility Mag 6 North Island East Coast. Confidence=low.
The forecast period is likely to be extended.

Update. 25 May 12.00am
24 May.
Christchurch/Avon Estuary 3.4 11.49am
Background tremor is very high in the North Island but solar wind is weak and the biggest local quake was down at the poo pond in Christchurch where it all got shaken up. The quake was felt across Christchurch.
Unusual tremor at Tongariro is a slight mystery. A minor degassing seems possible in the next days. Confidence= low. No webcam sign of any action at Tongariro but weather and visibility were bad.
Spaceweather is quiet ahead of a minor solar shock due late 25 May.
Sunspot AR2824, the source of several minor flares on 22 May has gone quiet and decayed. The Earth facing sunspot could still flare again although a major flare seems unlikely.
Mild geomagnetic storming and auroras seem likely to coincide with the 26 May supermoon and eclipse.
The supermoon will be overhead in the Southwest Pacific and in full eclipse at 11.15pm on Wednesday for 15 minutes.
The moon will be in partial eclipse for about 3 hours either side of the full eclipse.
This is the first supermoon eclipse in New Zealand for 40 years.
The forecast period is extended to 25 May.
Masterton, Castlepoint are added to Mag 4 risk locations.

Forecast. 24 May, 2021.
Magnitude 6 risk location is South of Kermadec Islands.
Magnitude 5 risk locations are East of East Cape, Te Kaha, Opotiki, Whakatane, Kawerau, Okataina, Rotorua, Tokoroa, Atiamuri, Matawai, Tolaga Bay, Napier, Hastings, Waipukurau, Porangahau, Dannevirke, Eketahuna, Eastern Taranaki Bight, Central Cook Strait, Cape Campbell, St Arnaud.
Magnitude 4 risk locations are East Cape, Tokomaru Bay, Mahia, Taupo, Taumarunui, Hawera, South of Taranaki, Kaikoura, Hanmer, Doubtful Sound, Northwest Arm Te Anau, Bligh Sound.
Degassing or minor steam eruption possible White Island.
Conditions are likely to build to a peak 26 May.