Magnitude 4.3 Earthquake on the Gulf of Corinth.

The United States Geological Survey detected a Magnitude 4.3 Earthquake at a depth of 10 km close to the northern shore of the Gulf of Corinth, slightly before 6.05 am local time (slightly before 3.05 am GMT) on Saturday 10 May 2014. People have reported feeling shaking up to 30 km from the epicenter of this event, but there are no reports of any damage or casualties.

The approximate location of the 10 May 2014 Gulf of Corinth Earthquake. Google Maps.

The geology beneath the Gulf of Corinth is slightly complicated. The Gulf forms part of the boundary between the Aegean and Eurasian Plates. This is a divergent margin, with the two plates moving apart, causing sinking in the centre of the Gulf, with the rocks on either side sinking along a series of faults, a structure known as a graben to geologists.

However this is not the whole story, as to the south of The Peloponnese the African Plate is being subducted beneath the Aegean Plate along the Hellenic Subduction Zone, passing under The Peloponnese and the Gulf of Corinth (note this is oceanic plate attached to the north of Africa, not the continental African Plate).

Thus there are two potential causes of Earthquakes beneath the Gulf of Corinth; shallow faulting associated with the graben caused by the drawing apart of the Aegean and Eurasian Plates, and a deeper zone where friction between the subducting African Plate and the overlying Aegean and Eurasian Plates can lead to quakes. However depth is not the only guide to the cause of a quake, as the friction of the African Plate passing under the Aegean and Eurasian Plates also exerts stresses on the rocks in the graben, and can contribute to quakes there.

See also...

 Magnitude 4.5 Earthquake under the Ionian Sea.

The United States Geological Survey recorded a Magnitude 4.5...

 Earthquake on the Gulf of Corinth.

On Saturday 22 September 2012, slightly after 6.50 am local time (slightly after 3.50 am, GMT) a Magnitude 5.1 Earthquake hit central Greece, slightly to the north of the Gulf of Corinth and roughly 100 km northwest of Athens, at a depth of about 10 km, according to the United States Geological Survey. This is a fairly large quake, and quite shallow, with the potential to cause serious damage to...

 Earthquake in the Gulf of Corinth, Greece. 7 August 2011.

At roughly 5.35 pm local time on Sunday 7 August 2011 an earthquake with a magnitude of 5.0 on the Richter Scale occurred beneath the Gulf of Corinth in Greece. Reports on the depth of this quake vary, with the United States Geological Survey giving a depth of 13.1 km and the Centre...

Follow Sciency Thoughts on Facebook.

Texas Tornado kills six.

A tornado described as a 4 on the Enhanced Fujita Scale (wind seeds between 267 and 322 kph) by the National Weather Service, hit the north Texas town of Granbury on the evening of Wednesday 15 May 2013, devastating the Rancho Brazos neighborhood and killing six people. 58 properties were either destroyed or damaged (out of 110 in the subdivision) and 37 more people hospitalized, at least six more people are still missing. At least 16 tornadoes were produced by the 15 May storm, though no others appear to have caused as much damage as the one which hit Rancho Brazos.

Rescue workers searching through the remains of a house in Granbury, Texas, on 16 May 2013. Brandon Wade/Reuters.

Tornadoes are formed by winds within large thunder storms called super cells. Supercells are large masses of warm water-laden air formed by hot weather over the sea, when they encounter winds at high altitudes the air within them begins to rotate. The air pressure will drop within these zones of rotation, causing the air within them so rise, sucking the air beneath them up into the storm, this creates a zone of rotating rising air that appears to extend downwards as it grows; when it hits the ground it is called a tornado. Tornadoes can occur anywhere in the world, but are most common, and most severe, in the area of the American mid-west known as 'Tornado Ally', running from Texas to Minnisota, which is fueled by moist air currents from over the warm enclosed waters of the Gulf of Mexico interacting with cool fast moving jet stream winds from the Rocky Mountains. Many climatologists are concerned that rising temperatures over the Gulf of Mexico will lead to more frequent and more severe typhoon events.

The air currents over Tornado Alley. University of Illinois at Urbana Champaign. 

See also Cyclone Evan kills at least two in Samoa, Hurricane Sandy heads towards east coast of America, Typhoon Bopha sweeps across the southern Philippines, Tropical Storm Son-Tinh kills at least 24 in the Philippines and Hurricane Sandy causes devastation in Jamaica.

Follow Sciency Thoughts on Facebook.

Earthquake on the Gulf of Corinth.

On Saturday 22 September 2012, slightly after 6.50 am local time (slightly after 3.50 am, GMT) a Magnitude 5.1 Earthquake hit central Greece, slightly to the north of the Gulf of Corinth and roughly 100 km northwest of Athens, at a depth of about 10 km, according to the United States Geological Survey. This is a fairly large quake, and quite shallow, with the potential to cause serious damage to buildings and potentially fatalities (the USGS estimate that a quake of this scale in this location would have a 32% chance of causing the loss of at least one life), though no damage or casualties have been reported on this occasion.

Map showing the location of the 22 September 2012 quake, and the areas likely to have suffered the most severe effects. Damage to buildings is likely within the innermost, green, circle.  USGS.

The geology beneath the Gulf of Corinth is slightly complicated. The Gulf forms part of the boundary between the Aegean and Eurasian Plates. This is a divergent margin, with the two plates moving apart, causing sinking in the centre of the Gulf, with the rocks on either side sinking along a series of faults, a structure known as a graben to geologists.

The graben beneath the Gulf of Corinth. The drawing apart of the Aegean and Eurasian Plates causes the lithosphere under the Gulf to thin, and the rocks of the crust to sink, splitting along a series of concentric faults on either side of the Gulf. Moretti et al. (2003).

However this is not the whole story, as to the south of The Peloponnese the African Plate is being subducted beneath the Aegean Plate along the Hellenic Subduction Zone, passing under The Peloponnese and the Gulf of Corinth (note this is oceanic plate attached to the north of Africa, not the continental African Plate).

The subduction of the African Plate beneath the Aegean Plate and the Gulf of Corinth. Turner et al. (2010).

Thus there are two potential causes of Earthquakes beneath the Gulf of Corinth; shallow faulting associated with the graben caused by the drawing apart of the Aegean and Eurasian Plates, and a deeper zone where friction between the subducting African Plate and the overlying Aegean and Eurasian Plates can lead to quakes. However depth is not the only guide to the cause of a quake, as the friction of the African Plate passing under the Aegean and Eurasian Plates also exerts stresses on the rocks in the graben, and can contribute to quakes there.

See also Earthquake rattles Crete, A new study of the Santorini eruption that destroyed ancient Minoa, Dodecanese Islands and Crete shaken by Earthquake, Earthquake in the Gulf of Corinth, Greece. 7 August 2011 and Earthquakes on Sciency Thoughts YouTube.

Follow Sciency Thoughts on Facebook.

Earthquake in the Gulf of Corinth, Greece. 7 August 2011.

At roughly 5.35 pm local time on Sunday 7 August 2011 an earthquake with a magnitude of 5.0 on the Richter Scale occurred beneath the Gulf of Corinth in Greece. Reports on the depth of this quake vary, with the United States Geological Survey giving a depth of 13.1 km and the Centre Sismologique Euro-Méditerranéen giving a depth of 5 km. Either way this was a shallow quake with the potential to be very dangerous. As it was there are no reports of any casualties or significant damage, but residents on both sides of the Gulf reported severe shaking with things falling from shelves etc.

Intensity map for the Gulf of Corinth quake. The purple star marks the site of the quake, the circles places where people reported feeling the quake. Larger circles indicate more people felt the quake, and the colour represents the intensity felt by the reporter.

Southern Greece and Turkey lie on the boundary between the Eurasian and African Plates on two smaller plates, the Aegean Sea Plate (underlying the Peloponnese, Attica, The Cyclades Islands, Crete, the Dodecanese Islands and Turkey to the southeast of the Taurus Mountains) and the Anatolian Plate (underlying most of the rest of Turkey). Northern Greece and the north coast of Turkey lie on the Eurasian Plate. Both countries are highly prone to earthquakes because of this.

The Aegean Sea and Anatolian Plates.

The Aegean Sea Plate is moving southwest with regard to the Eurasian and Anatolian Plates, and being subducted beneath the African Plate to the south. Its margin with the Eurasian Plate is a divergent and a transform margin at different points. Beneath the Gulf of Corinth it is a transform margin, where the plates are moving apart. In theory such a margin has the potential to become a new ocean, such as the Atlantic, with two continental plates moving apart and a rift zone creating new oceanic crust in between. However this is unlikely to be the fate of the Gulf of Corinth, as the Eurasian Plate is moving south over it (albeit at a slower rate than the Aegean Sea Plate is drawing away), the African Plate is advancing on it from the south, with the Aegean Sea Plate being subducted and destroyed beneath it, and the Anatolian Plate is moving in from the East.

Greece has a long history of Earthquakes. The most recent earthquake related fatality in Greece was in July 2008, when a woman was killed in an earthquake in Rhodes. In June the same year an earthquake on the Gulf of Corinth killed two people and made 2000 more homeless. In the past earthquakes in Greece have tens of thousands of people, caused tsunamis which have devastated the Egyptian and Levantine coasts and destroyed the Colossus of Rhodes. An earthquake which destroyed much of Sparta was one of the events leading up to the Peloponnesian War.

See also Torino (Turin) rocked by mild Earthquake, Recent eruptions on Mount Etna and Earthquakes on Sciency Thoughts YouTube.