Magnitude 5.3 Earthquake in northern Iraq.

The United States Geological Survey recorded a Magnitude 5.3 Earthquake at a depth of 8.3 km, 2 km to the north of Baynjiwayn in Sulaymaniyah Province, in the Kurdistan Region of Iraq, close to the border with Iran, slightly after 6.10 pm local time (slightly after 3.10 pm GMT) on Tuesday 6 April 2021. The event was felt on both sides of the Iranian border, but there are no reports of any damage or casualties.

 

The approximate location of the 6 April 2021 Sulaymaniyah Earthquake. USGS.

Iraq is situated on the northern part of the Arabian Plate, which is being pushed northward by the impact of Africa from the south, forcing it into the southern margin of the Eurasian Plate. This has created a zone of faulting and fold mountains along the northeast border of the country and neighbouring areas of Iran, known as the Zagros Thrust Belt. This compressing the rock layers close to the surface and creates frequent Earthquakes, some of which can be very large. 

 

The movement of the Arabian Plate and extent of the Zagros Thrust Belt. Rasoul Sorkhabi/Geo ExPro.

See also...

Follow Sciency Thoughts on Facebook.

Follow Sciency Thoughts on Twitter. 

 

Magnitude 3.8 Earthquake in Mineral County, Nevada.

The United States Geological Survey recorded a Magnitude 3.8 Earthquake at a depth of 7.8 km in Mineral County in western Nevada, slightly after 4.10 pm local time on Friday 25 April 2014 (slightly after 0.10 am on Saturday 26 April, GMT). There are no reports of any damage or injuries associated with this quake, but it was felt across much of Mineral County.

The approximate location of the 25 April 2014 Mineral County Earthquake. Google Maps.

Nevada is a zone of active mountain orogeny (mountain growth), fueled by the subduction zone on the American West Coast. The state is criss-crossed by faults associated with its many growing mountain ranges, which form part of the Rockies. The rocks of the North American lithosphere are being pushed to the east by seafloor spreading beneath the Pacific and to the west by seafloor spreading beneath the Atlantic. This results in folding and upthrust within the plate, principally in the Rocky Mountains, which run along the western margin of the North American Plate, close to the subduction and fault zones of the continent's west coast. This folding and thrusting leads to frequent Earthquakes throughout the Rocky Mountain region, with Nevada being one of America's most quake-prone states.

Witness accounts of quakes can help geologists to understand these events and the rock structures that cause them. If you felt this quake (or if you wee in the area but did not, which is also useful information) you can report it to the USGS here.

See also...

 Magnitude 4.9 Earthquake in Custer County, Idaho.

 Los Angeles shaken by Magnitude 4.4 Earthquake.

 Magnitude 4.5 Earthquake in northern Sonoma County, California.

Follow Sciency Thoughts on Facebook.

Magnitude 4.2 Earthquake in eastern Austria.

The Zentralanstalt für Meteorologie und Geodynamik recorded a Magnitude 4.2 Earthquake at a depth of 14 km, close to the town of  Mitterndorf an der Fischa in Baden District in eastern Austria, roughly 26 km south of Vienna, slightly after 7.15 pm local time (slightly after 5.15 GMT) on Wednesday 2 October 2013. This was followed by a Magnitude 2.9 aftershock slightly after 9.40 pm local time, and a second, Magnitude 1.9 aftershock slightly before 2.20 am. These are not large events, and did not lead to any damage or casualties, but were felt locally.

The approximate location of the 2 October 2013 Mittendorf an der Fischa Earthquake. Google Maps.

Baden District is located on the eastern fringe of the Alps, which are not static structures, but are a growing range of mountains being forced upwards by the impact of Africa into Europe, which is forcing the Adriatic Plate, underlying western Italy and the eastern Balkan Peninsula, further into the Eurasian Plate, causing folding and uplift in the rocks of central Europe. This movement is not smooth and continuous, but bumpy and jerky, as the rocks stick to one another while pressure builds up, then release suddenly causing quakes.

See also Magnitude 4.6 Earthquake in western Romania, Magnitude 4.5 Earthquake off the Adriatic Coast of Italy, Magnitude 3.9 Earthquake in Tuscany, Magnitude 3.7 Earthquake in the Tyrol, Austria and Earthquake in northern Italy.

Follow Sciency Thoughts on Facebook.

Magnitude 4.1 Earthquake in western Iran.

The United States Geological Survey recorded a Magnitude 4.1 Earthquake at a depth of 10.3 km in the Zagros Mountains in western Iran, at about 4.55 am local time (0.25 am GMT) on Friday 13 September 2013. There are no reports of any damage or casualties arising from this event, though it is likely to have been felt locally.

The approximate location of the 13 September 2013 Zagros Mountains Earthquake. Google Maps.

The Zagros Mountains are the result of faulting and folding along the Zagros Thrust Belt, where the Arabian Plate to the southwest is being pushed into the Eurasian Plate to the northeast by the northward movement of the African Plate and rifting beneath the Red Sea. This thrusting and folding leads to uplift which is forming the mountains (mountain orogeny). It is not a smooth process, with rocks tending to remain stationary comparative to one-another until pressure builds up enough to overcome their inertia, causing Earthquakes in the process.

Diagrammatic cross section through the Zagros Thrust Belt. Sarkarinejad & Azizi (2008).

To the northeast of this the geology is dominated by three large tectonic blocks, the Central Iran, Lut and Helmand, which move separately in response to pressure from the south, stretching and compressing the rock layers close to the surface and creating frequent Earthquakes, some of which can be very large.

See also Magnitude 4.9 Earthquake under the Caspian Sea, Magnitude 4.5 Earthquake in southern Fars Province, Iran, Magnitude 7.8 Earthquake in southeast Iran; high level of casualties expected, Magnitude 6.3 Earthquake in southern Iran kills at least 32 and Earthquake beneath the eastern Black Sea.

Follow Sciency Thoughts on Facebook.

Earthquake beneath the eastern Black Sea.

On Sunday 23 December 2012, slightly after 5.30 pm local time (slightly after 1.30 pm GMT) the United States Geological Survey recorded a Magnitude 5.5 Earthquake 10 km beneath the eastern Black Sea, roughly 35 km off the coast of Georgia. This is a fairly large quake for the area, but this far offshore is unlikely to have caused any damage or casualties. The quake was felt in Georgia, Turkey and Russia.

The location of the 23 December Earthquake. Google Maps.

The Black Sea is largely upon the Eurasian Plate, as are Georgia and Russia. Turkey, however, lies on a separate plate, the Anatolian Plate. This is being pushed to the west by the northward movement of the Arabian Plate, which is in turn being pushed by the African Plate, further to the south. This creates as zone of faulting along the northern part of Turkey, the North Anatolian Fault Zone, as the two plates are pushed past one-another (transform faulting). This is not a simple process, as the two plates constantly stick together, then break apart as the pressure builds up, leading to Earthquakes, which can be some distance from the actual fault zone.

How the movement of the Arabian Plate causes movement on the North Anatolian Fault Zone. Université Montpellier 2.

This northward movement of the African and Arabian Plates also causes folding and uplift in the Caucasus Mountains, which separate Georgia from Russia. Again this is not a smooth process, with the rocks sticking together, then moving sharply as the pressure builds up enough to break them appart, which can also lead to Earthquakes in the region.

See also Two major Earthquakes in northeast Iran, leading to heavy death toll, Earthquake in eastern Turkey, Earthquake off the Turkish coast, Earthquake in northwest Azerbaijan and Earthquakes on Sciency Thoughts YouTube.

Follow Sciency Thoughts on Facebook.

Canberra shaken by mild Earthquake.

On Friday 20 April at 5.09 am, local time (7.09 pm on Thursday 19 April GMT), the Australian capitol city, Canberra, was shaken by an Earthquake recorded by Geoscience Australia as measuring 3.7 on the Richter Scale and occurring 40 km west of the city at a depth of 4 km. There are no reports of any damage or casualties, but the quake was apparently felt across much of the city, as well as in the communities of Tumut, Murrumbateman, Batlow, Carwoola and Tuggeranong.

Map showing the location of the quake, and the area across which it was felt. Geoscience Australia.

While Canberra is a long way from any active tectonic plate margins, it is moderately Earthquake-prone. This is due to ancient folding of the rocks of the region, which has left many areas where the layers of strata are arranged vertically rather than horizontally, which is a less stable configuration. Typically strata lie flat, like a stack of books or magazines laid flat on a table. When geological movements turn these on their sides the resemble books or magazines lined up on a shelf, but without the shelf to provide a steady base. Such rocks are often prone to mild quakes.

See also Earthquake in Vanuatu, Earthquake shakes New Britain, Central Australia hit by major Earthquake, Earthquake shakes New Caledonia and Earthquakes on Sciency Thoughts YouTube.

Follow Sciency Thoughts on Facebook.