Earthquakes

News about earthquakes. The stronger events are edited manually by the author, but a part of the quakes are automatically detected and posted by the usgs.

Cumbre Vieja: Swarm quake on La Palma

by

Already on Saturday, the Volcanological Institute of the Canary Islands (INVOLCAN) has detected more than 50 earthquakes of low magnitude under the volcano Cumbre Vieja. The epicenters of the swarm were mainly located in the north of the volcano. They gathered in an elongated cluster that extends in a northwest-southeast direction. The hypocenters of the quakes were located at depths of around 30 km and thus in the area of the asthenosphere from which magma likes to rise into the earth’s crust. The strongest quake had the magnitude 1.2.

The scientists of INVOLCAN, however, reassure the population and say that the earthquake swarm is not a threat and that it does not indicate disturbing changes in the volcano. However, it should also be noted that increased carbon dioxide emissions were already registered in August. The quakes could well be related to magma intrusion.

Not only under La Palma it has been quaking more and more frequently for several months. Other regions of the Canary Islands are also affected. For example, there has been an accumulation of earthquakes in the area of El Hierro, on Tenerife (where there was a quake M 1.7 today) and under the sea floor between Tenerife and Gran Canaria. The quakes remind us that the volcanism of the region is only dormant and far from extinct.

Iceland: Earthquake M 5.6

by

On the Icelandic Reykjanes Peninsula, the earthquake struck this afternoon at 13.43 UCT with a magnitude of 5.6, with the epicenter located 3.9 km west of Krýsuvík and only a few kilometers from Grindavik. The hypocenter was located at a depth of 3.3 km. The quake could be felt in large parts of southwest Iceland and shook the capital. For Iceland it was a strong quake. There were numerous aftershocks, although I would honestly say that the main quake triggered a seismic swarm. So far 219 quakes have been registered, 12 with magnitudes greater than 3.

Alaska: Earthquake Mw 7,5

by

Off the coast of the US state of Alaska, the earth shook last night with a magnitude of 7.5, the epicenter being located 84 km southeast of Sand Point. This is a place on the Aleutian island of Unalaska. The hypocenter was at a depth of 40 km. Despite the relatively large depth of the earthquake epicenter there was a tsunami alarm. The same applies to larger damages. The region is only sparsely populated. In relative proximity to the location of the earthquake are some volcanoes that are classified as potentially active: Mount Makushin, Mount Okmok and the volcanic island of Bogoslof, to name only 3. The volcanism of the region is directly related to the Aleutian subduction zone where the earthquake occurred.

As is typical for earthquakes of this magnitude, there were numerous aftershocks. The strongest one had the magnitude 5.9 and further aftershocks must be expected.

La Palma: Seismic swarm

by

The Canary Island La Palma was again hit by a swarm quake yesterday morning. The seismographs recorded 25 tremors with magnitudes between 1.6 and 2.0. The hypocenters were at depths between 20 and 45 km. In this area of the asthenosphere, it is usually ascending magma that triggers light tremors. The epicenters were located in the south of the island, which was formed by eruptions.

In addition, seismicity is also increased in other regions of the Canary Islands. For example, it shook unusually often in the area of Tenerife and El Hierro is also still affected by sporadic quakes. Although there are no indications of an imminent volcanic eruption, in the longer term an eruption could occur again. In my opinion the most promising candidate is La Palma.

Bardarbunga: Earthquake M 4.8

by

Under the Icelandic glacier volcano Bardarbunga one of the strongest earthquakes of the last months occurred. It had a magnitude of 4.9 and its epicenter was 8.3 km east of the caldera. The epicenter of the earthquake was located at a depth of 4.8 km. A total of 12 earthquakes were recorded in the area of Vatanjökull within 48 hours.

Hasan Dağı: Gas emissions after earthquake

by

An unusual report from Turkey combines earthquake with volcanic activity. On Sunday, it shook in the border area of the provinces Aksaray and Niğde with a magnitude of 5.3. The epicenter was located 23 km northeast of Emirgazi. The epicenter of the earthquake was only 3 km deep. Almost 30 km northwest of the epicenter is the volcano Hasan Dağı. With a height of 3.268 m it represents the 2nd highest elevation of Central Anatolia. Videos make the round by the social media, which developed after the earthquake and show gas leaks. Apparently they are new fumaroles that have formed near the summit crater. A team of geologists will now take gas samples and analyze them. Gas eruptions occur repeatedly after earthquakes and need not be related to volcanism. On a volcano, however, one can assume that they are probably magmatic gases.

Los Angeles: Earthquake Mw 4,5

by

Yesterday morning, an earth tremor with a magnitude of 4.5 shook the greater Los Angeles area. The epicenter was 8 km east of Los Angeles. The depth of the epicenter was indicated by USGS as 18 km. According to the EMSC, the hypocenter was located at a depth of 20 km. In spite of the comparatively large depth of the focus, the earthquake was clearly perceived in the Los Angeles area. There are reports of small damages like cracks in house walls. Larger damages did not occur.

The earthquake manifested itself in the same fault zone as the 1987 Whittier Narrows earthquake, which had a magnitude of 5.9 and caused destruction in the city. The activated fault zone is the Puente Hills thrust fault, which is associated with the San Andreas Rift.

Translated with www.DeepL.com/Translator (free version)

Grimsvötn: Earthquake M 3.3

by

Tonight there was an earth tremor of magnitude 3.3 near Grimsvötn volcano. The epicenter was 11.1 km east of Hamarinn. The center of the earthquake was with 3.8 km relatively flat. Hamarinn is a subglacial volcano located in the west of the Icelandic glacier Vatnajökull and belongs to a system of crevasses that connects Grimsvötn and Bardarbunga. There have been 3 other weak earthquakes along the volcanic system.

Since a few weeks an increase of seismic activity at Grimsvötn can be observed. Volcanic experts assume that the volcano is preparing for an eruption. Whether and when a volcanic eruption will occur cannot be predicted yet.

Chile: Earthquake Mw 6,3

by

Another strong earthquake occurred in the Chilean region of Atacama. It had the magnitude 6.3 and was located 88 km north-north-east of Tocopilla. The depth of the earthquake is 45 km according to the EMSC. The earthquake occurred at 07:36 UCT. In Chile it was 04:36 UCT and the people were rudely torn from their sleep.

In the same area there had been an earthquake of magnitude 6.8 on September 1. One can assume that the two earthquakes are related. There were further aftershocks.

Several potentially active volcanoes are located in the Atacama. The Lascar is one of them. It showed signs of awakening at the beginning of the year and emitted heat radiation. The geyser field near the Tatio volcano is worth seeing.

Yellowstone Caldera: Yellowstone Caldera: Seismic swarm

by

Under the US-American Yellowstone Caldera a seismic swarm is manifesting itself today. The strongest quake to date was M 2.9. EMSC indicates a total of 12 quakes with magnitudes greater than 2. The hypocenters are located at shallow depths of less than 5 km. The epicenters are concentrated in a small area southwest of Yellowstone Lake. They are located in the area of Heart-Lake and Mount Sheridan. The depression of the lake was formed by folding processes at a young fault zone. Therefore the swarm quake could be of tectonic origin. However, there is also a thermal field at the lake, so hydrothermal influences could come into play. The Heart Lake Geyser Basin is also known for its thermophilic archaebacteria, which occur here in a basic environment.