Aotearoa Earthquake and Volcano Forecast Service

Aotearoa Summary. 13 July 2020 - 19 July 2020

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A Rolleston Mag 3 quake swarm justified the 14 July addition to risk locations.
The swarm came with the Papua New Guinea 7.0.
Christchurch quakes are generally well below Mag 4 and even Mag 3 swarms are becoming uncommon in 2020.
The 10th anniversary of the 4 September 2010 Darfield 7.1, driving the long term action, is just around the corner.
Spaceweather during the period was patchy and fluctuating, starting strongly with auroras on 14 July but fading out below expectations.
Frequent quakes in familiar North Island slow slip location Porangahau indicate a minor slow slip quake event may be underway...more frequent but lower magnitude quakes.
Pyke River Mag 5 risk location was quiet.
16 July.
Porangahau 4.3 1.42pm
17 July.
Prebbleton 2.9 12.07pm
Prebbleton 3.0 7.05pm
18 July.
Rolleston 3.1 12.08am
19 July.
Lyttelton 2.8 10.28pm

Update. 18 July 12.30am
17 July.
Prebbleton 2.9 12.07pm
Prebbleton 3.0 7.05pm
18 July.
Rolleston 3.1 12.08am
A Rolleston Mag 3 quake swarm has come with the mid afternoon Papua New Guinea 7.0.
Good location success picking Rolleston but local quake conditions are tricky.
A slow slip quake event may be underway in Northern Wairarapa with uncertain outcome.
Spaceweather is fading so the period is closing but a late quake is possible.
Due to the uncertainty of a possible slow slip event in Wairarapa and pressure in Canterbury the forecast period is extended to 18 July.
All risk locations and magnitudes are unchanged.

Update. 17 July 12.00am
16 July.
Porangahau 4.3 1.42pm
Spaceweather forecasted for 16 July never arrived.
Limited quake action is the result although the addition of extra Wairarapa risk locations is justified.
Spaceweather may increase and become fluctuating 17 July. Confidence=low.
Late quake action is possible.
Mag 5 remains possible.

Update. 15 July 11.00am
Local quakes are quiet.
Substantial spaceweather has eased overnight but due to pick up again about now.
A buildup is underway.
The outlook for a quake peak 16 July remains.
Snares Islands are added to Mag 5 risk locations.
Tokoroa, Taupo, Dannevirke, Eketahuna are added to Mag 4 risk locations.

Update. 14 July 11.30am
Spaceweather has set in this morning and is enough to drive quakes and eruptions.
Rolleston, Lake Coleridge are added to Mag 4 risk locations.

Forecast.
Magnitude 5 risk location is George Sound, Bligh Sound, Northwest Arm Te Anau.
Magnitude 4 risk locations are Pyke River, Cascade River, Lower Arawhata River, Seaward Kaikouras, Waipukurau, Gisborne, East Cape, Te Kaha, Taumarunui.
Volcanos quiet.
The period may build to a peak 16 July.