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2022-03-21, M5.2, North Sea

On the 21st of March 2022 at 06:32 UTC a magnitude M5.2 earthquake occurred in the North Sea, approximately 205 km WNW of Bergen, Norway. The earthquake located with a depth of 10 km and was reported felt from the western parts of southern Norway. The earthquake location is indicated by the red circle in the map below. The North Sea has low to intermediate seismicity with the majority of it occurring along the Norwegian coastline. Events are generally below M3 however a similar magnitude event was recorded in the same region on the 24th January 1927.

The event was recorded by seismic stations worldwide, including stations in the Irish National Seismic Network (INSN) (see figure below). The first seismic waves originating from the North Sea earthquake arrived in Ireland ~2 minutes after the event origin.

For more information on the North Sea earthquake please see these links:

https://earthquake.usgs.gov/earthquakes/eventpage/us6000h6bi/executive

https://www.emsc-csem.org/Earthquake/earthquake.php?id=1109087

https://nnsn.geo.uib.no/nnsn/#/news

2022-03-16, M7.3, Japan

At 14:36:33 (UTC) on the 16th of March 2022 a magnitude 7.3 earthquake occurred near the east coast of Honshu Japan, 57 km east-north-east of Namie which is located in Fukushima Prefecture (see map below). The NWS Pacific Tsunami Warning Center initially issued a warning for hazardous waves along the coast of Japan but now reports the threat from this event has passed. The Tokyo Electric Power Company reports over 2 million households in nine prefectures have been left without electricity due to the earthquake.

Japans tectonic setting is complex as it is influenced by the North America plate, Pacific plate, Philippine Sea plate, and Eurasian plate. A detailed summary of the region is available from the USGS at the following link https://earthquake.usgs.gov/earthquakes/eventpage/us6000h519/region-info.

The event was recorded by seismic stations worldwide, including stations in the Irish National Seismic Network (INSN) (see figure below). The first seismic waves originating from the Japan earthquake arrived in Ireland ~15 minutes after the event origin.

For more information on the M7.3 Japan earthquake please see these links:

https://earthquake.usgs.gov/earthquakes/eventpage/us6000h519/executive?utm_medium=email&utm_source=ENS&utm_campaign=realtime

https://www.jma.go.jp/bosai/map.html#5/38.393/143.174/&elem=warn&contents=tsunami&lang=en

http://geofon.gfz-potsdam.de/eqinfo/event.php?id=gfz2022fgid

https://www.emsc-csem.org/Earthquake/earthquake.php?id=1107417

2022-01-15, Eruption in Tonga

The underwater volcano “Hunga Tonga-Hunga Ha’apai” in Tonga has been experiencing ongoing volcanic activity since the 20th December 2021. From the 5th of January 2022 activity had decreased, but on the 15th it increased again with a large eruption occurring with a sonic boom that was heard hundreds of kms away. The event was recorded by seismic stations worldwide, including stations in the Irish National Seismic Network (INSN) (see figure below). The first signals originating from the Tonga event arrived ~15 hours after the event origin. A large plume of ash was visible on satellite images and the eruption was heard in Tonga, the surrounding islands and with reports from as far away as Alaska. The eruption also generated a tidal wave warning for the Pacific region.

2021-11-16, M3.3, Scotland

On the 16th of November 2021 at 01:44 UTC a magnitude 3.3 earthquake occurred in Western Scotland. The earthquake located with a depth of approximately 6 km and is indicated by the red circle in the map below. There have been reports of the event being felt in Scotland and Northern Ireland.

The event was recorded by the stations of the Irish National Seismic Network (INSN) and can be seen in the waveforms plotted below:

Listen to Dr Martin Möllhoff discussing this event on RTE Radio 1’s Morning Ireland show here:

https://www.rte.ie/radio/radio1/clips/22030318/

More information is available from:


https://earthquake.usgs.gov/earthquakes/eventpage/us7000fugg/executive

https://www.emsc.eu/Earthquake/earthquake.php?id=1062853

http://www.earthquakes.bgs.ac.uk/earthquakes/recent_events/20211116014340.html#page=summary

2021-07-29, M8.2, Alaska

On July 29, 2021 at 06:15 UTC (July 28, 2021 22:51 local time) a magnitude 8.2 earthquake occurred approximately 80km south of the Alaska Penninsula (see map below). The USGS report the earthquake originated at a depth of 32 kilometers. Large earthquakes are common in this region as a result of thrust faulting at shallow depth on the subduction zone interface between the Pacific plate and the North America plate.

The event was recorded by seismic stations worldwide, including stations in the Irish National Seismic Network (INSN) (see figure below). The first seismic waves originating from the Alaska earthquake arrived ~6 minutes after the event origin.

For more information please see the links below:

https://www.usgs.gov/news/magnitude-82-earthquake-alaska

https://www.emsc-csem.org/Earthquake/earthquake.php?id=1014588

2021-03-04, M8.1, Kermadec Islands

At 19:28 on the 4th March 2021 a magnitude 8.1 earthquake occurred in the Kermadec Islands region. This follows two other strong events in the region today, an M7.3 event which occurred further south close to the North Island of New Zealand (see here) and an M7.4 event that also occurred in the Kermadec Islands region (see here).

New Zealands National Emergency Management Agency (NEMA) have issued a statement advising people on the east coast of the north island to move to higher ground. The earthquake had a depth of 10 km, shallow earthquakes like this present a tsunami threat.

The event was recorded by seismic stations worldwide, including stations in the Irish Nation Seismic Network (INSN) (see figure below).

The earthquake occurred along the eastern margin of the Australia plate where it meets the Pacific plate. The convergence of the two plates means the region is prone to large events such as this (there have been 15 earthquakes with magnitude greater than 7.5 since 1900).

For more information see the following:

https://earthquake.usgs.gov/earthquakes/eventpage/us7000dflf/executive

https://www.emsc-csem.org/Earthquake/earthquake.php?id=955088

https://www.civildefence.govt.nz/

2021-03-04, M7.3, New Zealand

At 13:27 on 4th March 2021 a magnitude 7.3 earthquake occurred off the East coast of the New Zealand’s Northern Island (see map below). The Pacific Tsunami Warning Center (PTWC) immediately issued a warning for the possibility of hazardous Tsunami waves within 300 km of the earthquake epicenter along the New Zealand coast. Tsunami waves of 0.28 m were then observed on the Northeastern Cape and waves of 0.3 to 3 m have been forecast.

The event was recorded by seismic stations worldwide. The stations in the Irish Nation Seismic Network (INSN), recorded it approximately 20 minutes after it occurred (see figure below).

New Zealand is on the Eastern margin of the Australian plate and the region is prone to large events such as this (there have been 15 earthquakes with magnitude greater than 7.5 since 1900). The convergence of the Australia and Pacific plates make it one of the most seismically active areas in the world.

For more information see the following:

https://earthquake.usgs.gov/earthquakes/eventpage/us7000dffl/executive

https://www.geonet.org.nz/earthquake/2021p169083

https://www.emsc-csem.org/Earthquake/earthquake.php?id=954885


2021-02-24, M5.7, Iceland

The Reykjanes Peninsula in Iceland has suffered a series of earthquakes in the past few hours. This phenomena is known as an earthquake swarm. At the time of writing, there have been 725 quakes in the last 48 hours. The largest of which was a magnitude 5.7 that occurred at 10:05:57 on the 24th February 2021. This event was recorded by the Irish National Seismic Network and can be seen in the waveforms plotted below.

Waveforms from the magnitude 5.7 Icelandic event recorded on the 6 INSN instruments.

More information is available from the Icelandic Met Office:

https://en.vedur.is/about-imo/news/earthquake-swarm-in-reykjanes-peninsula

and on this webpage:

https://www.ruv.is/frett/2021/02/24/earthquake-alert-level-increased

present earthquake activity on the Reykjanes peninsula is shown here:

https://en.vedur.is/earthquakes-and-volcanism/earthquakes/reykjanespeninsula#view=map

2020-10-30, M7.0, Greece

At 11:51:26 (UTC) on the 30th of October 2020, a magnitude 7.0 earthquake occurred 14 km NE of Néon Karlovásion, Greece (see map below). Early reports state that there has been building collapse and a sea surge that flooded streets in the Turkish resort city of Izmir. The Mediterranean region is prone to such events due to the northward convergence of the African plate with respect to the Eurasian plate along a complex plate boundary.

The earthquake was recorded at seismic stations worldwide, including stations of the Irish Nation Seismic Network (INSN), see seismic waveforms below.

Further information is available from the following sources:

https://earthquake.usgs.gov/earthquakes/eventpage/us7000c7y0/executive

https://www.emsc-csem.org/Earthquake/earthquake.php?id=915787


2020-10-19, M7.5, Alaska

At 20:54:40 (UTC) on the 19th of October 2020, a magnitude 7.5 earthquake occurred near the Alaska Peninsula (see map below). The earthquake struck approximately 90 km south of the peninsula at a depth of 40 km. Initially a tsunami threat warning was issued by the Pacific Tsunami Warning Center, however it is now thought this threat has passed. The Alaska Peninsula is prone to large earthquakes due to the subduction of the Pacific plate beneath the North American plate in that region.

Location of the M7.5 Alaska earthquake.

The earthquake was recorded at seismic stations worldwide, including stations of the Irish Nation Seismic Network (INSN), see seismic waveforms below.

Seismic waveforms recorded by the INSN (click to enlarge).

Further information is available from the following sources:

https://earthquake.usgs.gov/earthquakes/eventpage/us6000c9hg/executive?utm_medium=email&utm_source=ENS&utm_campaign=realtime

https://www.emsc-csem.org/Earthquake/earthquake.php?id=912660

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