Sunday, 28 May 2017

Magnitude 5.0 Earthquake in Izmir Province, Turkey.

The United States Geological Survey recorded a Magnitude 5.0 Earthquake at a depth of 10 km, about 7 km to the west of the  town of Gölmarmara in Izmir Province, southwest Turkey, slightly after 6.50 pm local time (slightly after 3.50 pm GMT) on Saturday 27 May 2017. There are no reports of any fatalities associated with this event, but at least one person injured and a number of buildings destroyed. The event was felt across much of western Turkey. 

Damage following the 27 May 2017 Izmir Earthquake. Daily Sabah.

The majority of Asian Turkey lies on the Anatolian Plate, which 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 Anatolian Plate is pushed past the Eurasian Plate, which underlies the Black Sea and Crimean Peninsula  (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.

The approximate location of the 27 May 2017 Izmir Province Earthquake. USGS.

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.

Plate movements and fault zones around the Anatolian Plate. Mike Norton/Wikimedia Commons.

Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. The international non-profit organisation Earthquake Report is interested in hearing from people who may have felt this event; if you felt this quake then you can report it to Earthquake Report here.
See also...
http://sciencythoughts.blogspot.co.uk/2016/09/magnitude-52-earthquake-off-northwest.htmlhttp://sciencythoughts.blogspot.co.uk/2014/06/magnitude-50-off-southeast-coast-of.html
http://sciencythoughts.blogspot.co.uk/2014/06/a-volcanically-preserved-rhinoceros.htmlhttp://sciencythoughts.blogspot.co.uk/2014/06/does-catalhoyuk-mural-depict-volcanic.html
http://sciencythoughts.blogspot.co.uk/2014/05/magnitude-69-earthquake-beneath-north.htmlhttp://sciencythoughts.blogspot.co.uk/2014/05/hundreds-dead-following-explosion-at.html
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Garbage truck falls into sinkhole in Augusta, Georgia.

A garbage truck became trapped in a sinkhole in Augusta, Georgia, after a section of road collapsed beneath it at about 8.00 am local time on Thursday 25 May 2017. Nobody was hurt in the incident and the vehicle has subsequently been removed, but the section of road where it occurred is likely to remain closed for some time while engineers assess the situation and repairs are carried out.

The scene of the 25 May 2017 Augusta sinkhole. Doug Stutsman/The Augusta Chronicle.

Sinkholes are generally caused by water eroding soft limestone or unconsolidated deposits from beneath, causing a hole that works its way upwards and eventually opening spectacularly at the surface. Where there are unconsolidated deposits at the surface they can infill from the sides, apparently swallowing objects at the surface, including people, without trace.

However on this occasion the sinkhole is believed to have been caused by a damaged sewer or storm drain, which leaded water that washed away soft sediments beneath the road until it collapsed. A number of houses in the area have been left without water following the event.  

See also...

http://sciencythoughts.blogspot.co.uk/2017/04/chemical-spill-closes-atlanta-downtown.htmlhttp://sciencythoughts.blogspot.co.uk/2016/09/tropical-storm-hermine-makes-landfall.html

http://sciencythoughts.blogspot.co.uk/2016/08/alabama-river-hit-by-sulphuric-acid.htmlhttp://sciencythoughts.blogspot.co.uk/2016/08/florida-state-department-of-health.html
http://sciencythoughts.blogspot.co.uk/2015/11/sinkhole-swallows-car-in-jacksonville.htmlhttp://sciencythoughts.blogspot.co.uk/2015/10/homes-evacuated-after-sinkhole-appears.html
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Saturday, 27 May 2017

Asteroid 2017 KY4 passes the Earth.

Asteroid 2017 KY4 passed by the Earth at a distance of  948 300 km (2.47 times the average distance between the Earth and the Moon, 0.63% of the average distance between the Earth and the Sun), slightly before 3.50 pm GMT on Saturday 20 May 2017. There was no danger of the asteroid hitting us, though had it done so it would have presented no threat. 2017 KY4 has an estimated equivalent diameter of 22-68 m (i.e. it is estimated that a spherical object with the same volume would be 22-68 m in diameter), and an object of this size would be expected to explode in an airburst (an explosion caused by superheating from friction with the Earth's atmosphere, which is greater than that caused by simply falling, due to the orbital momentum of the asteroid) in the atmosphere between 20 and 3 km above the ground, with only fragmentary material reaching the Earth's surface.

 
The calculated orbit of 2017 KY4. Minor Planet Center.

2017 KY4 was discovered on 22 May 2017 (two days after its closest approach to the Earth) by the University of Arizona's Mt. Lemmon Survey at the Steward Observatory on Mount Lemmon in the Catalina Mountains north of Tucson. The designation 2017 KY4 implies that the asteroid was the 124th object (object Y4) discovered in the second half of May 2017 (period 2017 K).

2017 KY4 has an 406 day orbital period and an eccentric orbit tilted at an angle of 17.5° to the plane of the Solar System, which takes it from 1.002 AU from the Sun (i.e. 100.2% of he average distance at which the Earth orbits the Sun) to 1.15 AU from the Sun (i.e. 115% of the average distance at which the Earth orbits the Sun). It is therefore classed as an Amor Group Asteroid (an asteroid which comes close to the Earth, but which is always outside the Earth's orbit). This means that close encounters between the asteroid and Earth are fairly common, with the most recent having occurred in November 2007 next predicted in November this year.

See also...

http://sciencythoughts.blogspot.co.uk/2017/05/asteroid-2017-jv1-passes-earth.htmlhttp://sciencythoughts.blogspot.co.uk/2017/05/comet-c2015-er61-panstarrs-reaches.html
http://sciencythoughts.blogspot.co.uk/2017/05/asteroid-2017-ja-passes-earth.htmlhttp://sciencythoughts.blogspot.co.uk/2017/05/asteroid-448003-2008-de-passes-earth.html
http://sciencythoughts.blogspot.co.uk/2017/05/the-2017-eta-aquarid-meteors.htmlhttp://sciencythoughts.blogspot.co.uk/2017/04/asteroid-2017-gk4-passes-earth.html
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Sinkhole swallows car in Denver, Colorado.

A taxi was swallowed by a sinkhole in Denver, Colorado, in the early hours of Friday 26 May 2017, after the driver mistook the hole for a puddle caused by overnight rain, and drove into it. The driver was unhurt, and no passengers were in the vehicle at the time, but the taxi is thought likely to be written off after falling into the two meter hole.

Taxi trapped in a sinkhole in Denver, Colorado, on 26 May 2017. CBS News.

Sinkholes are generally caused by water eroding soft limestone or unconsolidated deposits from beneath, causing a hole that works its way upwards and eventually opening spectacularly at the surface. Where there are unconsolidated deposits at the surface they can infill from the sides, apparently swallowing objects at the surface, including people, without trace.

However on this occasion the sinkhole is believed to have been caused by a burst water main, which washed away soft sediments beneath the road until it collapsed. A number of houses in the area have been left without water following the event.

See also...
 
http://sciencythoughts.blogspot.co.uk/2016/12/museum-evacuated-after-chemical-spill.html
http://sciencythoughts.blogspot.co.uk/2017/01/motorcycle-crash-causes-major-sinkhole.html


http://sciencythoughts.blogspot.co.uk/2016/11/magnitude-50-earthquake-in-payne-county.html
http://sciencythoughts.blogspot.co.uk/2016/11/tourist-dies-after-falling-into-hot.html
http://sciencythoughts.blogspot.co.uk/2016/09/magnitude-56-earthquake-in-pawnee.html
http://sciencythoughts.blogspot.co.uk/2016/09/magnitude-38-earthquake-beneath-spencer.html

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Friday, 26 May 2017

Flooding and mudslides kill at least 91 in Sri Lanka.

At least 91 people have died and over 110 are missing after heavy rain triggered flooding and mudslides across central, western and southern parts of the country on Thursday 25 and Friday 26 May 2017. The worst incident occured in Bulathsinhala District in Western Province, where at least eleven people are known to have died in a single mudslide, while 38 people are reported to have died in flooding in Kalutara District in Central Province and 46 in Ratnapura District in Southern Province. Landslides are a common problem after severe weather events, as excess pore water pressure can overcome cohesion in soil and sediments, allowing them to flow like liquids. Approximately 90% of all landslides are caused by heavy rainfall.

The  aftermath of a landslide in the village of Bellana in Kalutara District, Sri Lanka, on 26 May 2017. Eranga Jayawardina/AP.
Eranga Jayawardena
Eranga Jayawardena
Eranga Jayawardena
Eranga Jayawardena
Eranga Jayawardena

The rains are associated with the onset of the Sri Lankan summer monsoon, which lasts from May to October, typically brining around 400 mm of rain to many parts of the country in an average year. Monsoons are tropical sea breezes triggered by heating of the land during the warmer part of the year (summer). Both the land and sea are warmed by the Sun, but the land has a lower ability to absorb heat, radiating it back so that the air above landmasses becomes significantly warmer than that over the sea, causing the air above the land to rise and drawing in water from over the sea; since this has also been warmed it carries a high evaporated water content, and brings with it heavy rainfall. In the tropical dry season the situation is reversed, as the air over the land cools more rapidly with the seasons, leading to warmer air over the sea, and thus breezes moving from the shore to the sea (where air is rising more rapidly) and a drying of the climate. 

Diagrammatic representation of wind and rainfall patterns in a tropical monsoon climate. Geosciences/University of Arizona.

See also...

http://sciencythoughts.blogspot.co.uk/2017/04/twenty-six-confirmed-dead-and-over.htmlhttp://sciencythoughts.blogspot.co.uk/2016/05/flooding-and-landslides-kill-at-least.html
http://sciencythoughts.blogspot.co.uk/2014/12/at-least-six-dead-following-landslide.html
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Thursday, 25 May 2017

Closest Lunar Perigee of 2017.

At 1.24 am GMT on Friday 26 May 2017 the Moon will be at its closest point to the Earth in 2017, at a distance of 357 209 km. his will fall five hours and forty minutes after the New Moon, at 7.644 pm on Thursday 25 May, making it effectively invisible. The Moon completes one orbit about the Earth every 27.5 days, and like most orbiting bodies, its orbit is not completely circular, but slightly elliptical, so that the distance between the two bodies varies by about 3% over the course of a month. This elliptical orbit is also not completely regular, it periodically elongates then returns to normal, making some perigees closer than others. These cycles mean that the Moon reached its furthest point from the Earth (apogee) of the year in the same lunar cycle, 406 401 km at 7.52 pm GMT on Thursday 8 June, which will be the second most distant Lunar Apogee of 2017.

 Simplified diagram of the Moon's orbit. NASA.

Although this is the closest point to the Earth that the Moon has reached this year, it is not exceptional. The Moon reached 356 511 km from the Earth on 14 November 2016, and will reach 357 122 km from the Earth on 10 March 2020.

See also...

http://sciencythoughts.blogspot.co.uk/2017/04/uranis-reaches-solar-conjunction.htmlhttp://sciencythoughts.blogspot.co.uk/2017/04/jupiter-at-opposition.html
http://sciencythoughts.blogspot.co.uk/2017/03/the-march-equinox.htmlhttp://sciencythoughts.blogspot.co.uk/2017/02/neptune-reaches-solar-conjunction.html
http://sciencythoughts.blogspot.co.uk/2017/02/annular-eclipse-to-be-visible-from.htmlhttp://sciencythoughts.blogspot.co.uk/2017/02/jupiter-approaches-aphelion.html
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Sunday, 14 May 2017

Magnitude 5.4 Earthquake in western Xinjiang Province, China, kills at least eight.

The United States Geological Survey recorded a Magnitude 5.4 Earthquake at a depth of 10.0 km in the Pamir Mountains of western Xinjiang Province, China, close to the borders with Tajikistan, Afghanistan and Pakistan, slightly before 6.00 am local time on Thursday 11 May 2017 (slightly before 9.00 pm on Wednesday 10 May, GMT). At least eight people are known to have died following this event, with another eleven injured and over 3000 houses destroyed.

Damage following the 10 May 2017 Xinjiang Earthquake. Xinhua.

The Pamir Mountains lie to the north of the boundary between the Indian and Eurasian tectonic plates, which runs through northern Afghanistan. The Indian Plate is moving northward relative to the Eurasian Plate, causing folding and uplift along this boundary, which has led to the formation of the Hindu Kush Mountains of Afghanistan, The Pamirs in Tajikistan, the Himalayas and the other mountain ranges of Central Asia., and which makes the nations in this boundary zone prone to Earthquakes.
 
 The approximate location of the 10 May 2017 Xinjiang Earthquake. USGS.

Witness accounts of Earthquakes can help geologists to understand these events, and the structures that cause them. The international non-profit organisation Earthquake Report is interested in hearing from people who may have felt this event; if you felt this quake then you can report it to Earthquake Report here.

See also...

http://sciencythoughts.blogspot.co.uk/2017/04/seven-conformed-deaths-as-heavy-rains.html
http://sciencythoughts.blogspot.co.uk/2017/04/landslide-kills-24-in-osh-region-of.html

http://sciencythoughts.blogspot.co.uk/2016/08/landslide-at-hindu-shrine-kills-at.html
http://sciencythoughts.blogspot.co.uk/2016/11/magnitude-66-earthquake-in-western.html
http://sciencythoughts.blogspot.co.uk/2016/08/landslide-kills-four-in-jammu-in-kashmir.html
http://sciencythoughts.blogspot.co.uk/2016/08/magnitude-52-earthquake-in-northwest.html


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