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2019-04-22, M6.1, Philippines

On the 22nd April 2019 an earthquake with magnitude 6.1 occurred at 09:11:11 UTC (17:11 local time) in Northern Philippines. The earthquake was at a depth of 20km and centered near the town of Castillejos in Zambales Province, west of Manila, the capital city. It has been reported that at least 11 people died. Strong earthquakes happen regularly in this region that are caused by the colliding tectonic plates -the Philippine Sea plate is bordered by the larger Pacific and Eurasia plates and the smaller Sunda plate.

Another earthquake occurred on the 23rd April at 05:37:52 (UTC) (1.37pm local time) measuring M6.4, with the epicentre at San Julian in eastern Samar. The US Geological Survey (USGS) said the quake measured magnitude 6.4 and there were no immediate reports of casualties or damage.

The earthquake was recorded at seismic stations worldwide, including stations of the Irish National Seismic Network (INSN), see seismic waveforms below (select figure to enlarge).

2018-08-19, M8.2, Fiji Region

On the August 18, 2018, M 8.2 earthquake near Fiji occurred as the result of deep, normal faulting approximately 560 km beneath the South Pacific Ocean several hundred kilometers to the west of the Tonga Trench. There were no reports of casualties.

Earthquakes that have focal depths greater than 300 km are commonly termed “deep-focus” earthquakes. Deep-focus earthquakes cause less damage on the ground surface above their foci than similar-magnitude shallow-focus earthquakes, but large deep-focus earthquakes may be felt at great distance from their epicenters.

 

The earthquake was recorded at seismic stations worldwide, including stations of the Irish National Seismic Network (INSN), see seismic waveforms below (select figure to enlarge).

2018-08-05, M6.9, Indonesia

On 5th August, 2018, an earthquake measuring magnitude 6.9 occured in the Lombok Region, Indonesia at 18:46 local time. Latest media reports that at least 91 people have been killed, many more have been injured and thousands of houses have been destroyed or damaged throughout the region. It hit just a few days after shallow M6.4 on July 28 in which 17 people died.

The earthquake was recorded at seismic stations worldwide, including stations of the Irish National Seismic Network (INSN), see seismic waveforms below (select figure to enlarge).

2018-02-25, M7.5 Papua New Guinea

On 25th February, 2018, an earthquake measuring magnitude 7.5 occurred at 4a.m local time, in a rural, jungle area of the Southern Highlands in New Guinea, Papaua New Guinea. It wasn’t immediately clear if there was damage. No tsunami watches or warnings were issued because of the quake.

At the location of this earthquake, the Australia plate is converging with the Pacific plate and it occurred as the result of thrust faulting at shallow a depth. Thrust-faulting events of the size of the February 25th, 2018 earthquake are typically about 85×30 km (length x width).

dias2018dxvu-map-no_stations-40deg

The earthquake was recorded at seismic stations worldwide, including stations of the Irish National Seismic Network (INSN), see seismic waveforms below (select figure to enlarge).

7-5_2018-02-25_056_174444-200_-6-08_142-79_35_4200_-720_0-01-none-1-none

2018-02-17, M4.4 South Wales

On the 17th February 2018 an earthquake with magnitude 4.4 occurred at 14:31:07.6 UTC at a depth of 7.4km in South Wales about 20km north of Swansea, see map below. According to the BGS  hundreds of members of the public submitted felt reports. Events of this magnitude happen in the UK only about every 2 to 3 years. The BGS reports that this is the biggest event in the area since a magnitude 5.2 earthquake in 1906.

dias2018dizj-map-no_stations-05deg
The earthquake was recorded at stations of the Irish National Seismic Network (INSN), see seismic waveforms below (select figure to enlarge).

4-4_2018-02-17_048_14-31-10-800_52-11-5-49_3_240_0_2-none-ei-none

Further information about this event is available from the following webpages:

BGS: http://earthquakes.bgs.ac.uk/earthquakes/recent_events/20180217142554.html#page=summary

EMSC: https://www.emsc-csem.org/Earthquake/earthquake.php?id=649041
GFZ: http://geofon.gfz-potsdam.de/eqinfo/event.php?id=gfz2018dizj

The drumplot below shows the unfiltered seismic signal recorded on the 17th February 2017 at INSN station DSB in the Dublin mountains. The high amplitude low frequency signals between midnight and 1 a.m. are the surface waves of the M7.2 Mexico earthquake that occurred on the 16th February 2018 at 23:39:39, see https://www.insn.ie/2017-02-16-m7-2-mexico for more details on that event. The magnitude 4.4 event with epicentre in South Wales can be seen with much higher frequency content around 14:32.

ei-dsb-hhz-d-2018-048-drum-17-02

More information about the INSN is available via this link.

2018-02-06, M6.4 Taiwan

On 6th February, 2018, an earthquake measuring magnitude 6.4 occurred northeast of Hualien, Taiwan. So far at least seven people have been killed and more than 250 injuries have been reported. Aftershocks continue to occur in Taiwan since the earthquake.

Taiwan lies in a region of complex tectonics near the intersection of three major tectonic plates – the Philippine Sea plate to the east and southeast, the Eurasia plate to the north and west, and the Sunda plate to the southwest. The February 6th 2018 earthquake is the largest in a sequence of events in the same region over the past several days. Because of its plate boundary location, Taiwan commonly experiences moderate-to-large earthquakes.

dias2018cozm-map-no_stations-12deg

The earthquake was recorded at seismic stations worldwide, including stations of the Irish National Seismic Network (INSN), see seismic waveforms below (select figure to enlarge).

2018-01-23, M8.0 Gulf of Alaska

A major earthquake with magnitude 8.0 occurred in the Gulf of Alaska on the 23rd January 2018 at 09:31:41 UTC at a depth of about 25km. A tsunami warning was issued but has been cancelled. The Aleutian arc extends approximately 3,000 km from the Gulf of Alaska in the east to the Kamchatka Peninsula in the west. It marks the region where the Pacific plate subducts into the mantle beneath the North America plate. This subduction is responsible for the generation of the Aleutian Islands and the deep offshore Aleutian Trench. The Aleutian arc is a seismically active region, evidenced by the many moderate to large earthquakes occurring each year.

The earthquake was recorded at seismic stations worldwide, including stations of the Irish National Seismic Network (INSN), see seismic waveforms below (select figure to enlarge).

Further information is available from the following webpages:

EMSC: https://www.emsc-csem.org/Earthquake/earthquake.php?id=642932
GFZ: https://geofon.gfz-potsdam.de/eqinfo/event.php?id=gfz2018boxy
USGS: https://earthquake.usgs.gov/earthquakes/eventpage/us2000cmy3#origin

More information about the INSN is available via this link.

2018-01-14, M7.2 Peru

A major earthquake with magnitude 7.2 occurred off the southern coast of Peru on the 14th January 2018 at 09:18:46 UTC at a depth of about 40km. The epicenter of this event lies about 30km from the coast of the Arequipa region, see map below. Tens of people have been injured and at least one fatality has been reported. No tsunami has been observed following this earthquake. Strong earthquakes are not uncommon in this region where the Nazca plate subducts beneath the South America plate at about 7 centimeters per year.

dias2018ayma-map-no_stations-30deg

The earthquake was recorded at seismic stations worldwide, including stations of the Irish National Seismic Network (INSN), see seismic waveforms below (select figure to enlarge).

7-2_2018-01-14_014_09_18_45-0_15-73_-74-61_41_5400_0_0-01-none-1-none

Further information is available from the following webpages:

EMSC: https://www.emsc-csem.org/Earthquake/earthquake.php?id=641183
GFZ: http://geofon.gfz-potsdam.de/eqinfo/event.php?id=gfz2018aylz
USGS: https://earthquake.usgs.gov/earthquakes/eventpage/us2000cjfy#executive

More information about the INSN is available via this link.

2018-01-10, M7.6 Honduras

A strong earthquake of magnitude 7.6 occurred on the 10th January 2018 at 02:51:32.1 UTC in the Caribbean Sea, about 200km from the northern coast of Honduras, see map below. A tsunami alert was first issued but has been lifted since. The event is due to movement on the North America-Caribbean plate boundary and was felt in Honduras, Guatemala, Costa Rica, El Salvador and some parts of Mexico. There are no reports of injuries or structural damage. dias2018aqre-map-no_stations-20deg

The earthquake was recorded at seismic stations worldwide, including stations of the Irish National Seismic Network (INSN), see seismic waveforms below (select figure to enlarge).

7-5_2018-01-10_010_025132-100_17-38_-83-5_12_5400_0_0-01-none-1-none

Further information is available from the following webpages:

EMSC: https://www.emsc-csem.org/Earthquake/earthquake.php?id=640330
GFZ: https://geofon.gfz-potsdam.de/eqinfo/event.php?id=gfz2018aqre
USGS: https://earthquake.usgs.gov/earthquakes/eventpage/us1000c2zy#executive

More information about the INSN is available via this link.

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