Chinese tourists killed as diving boat capsizes off the coast of Phuket, Thailand.

At least thirty three people have died and twenty three more are missing after a boat offering diving tours of the coral reefs around the island of Phuket in Thailand capsized after sailing into a tropical storm on Thursday 5 July 2018. The vessel, which was one of a number of such craft that ignored a warning about the storm, which brought with it waves up to five metres high, was carrying 110 Chinese tourists, plus one guide and eleven crew members. All of the confirmed dead are reported to be Chinese nationals, with divers from the Royal Thai Navy searching the vessel and surrounding waters for survivors, aided by local fishing vessels. A second boat, carrying 39 European tourists, also capsized, but all of the passengers and crew of that vessel have been accounted for.

Chinese tourists rescued by local fishermen after their tour vessel capsized, being transferred to a Thai Navy ship. CNN.

Tropical storms are caused by solar energy heating the air above the oceans, which causes the air to rise leading to an inrush of air. If this happens over a large enough area the in rushing air will start to circulate, as the rotation of the Earth causes the winds closer to the equator to move eastwards compared to those further away (the Coriolis Effect). This leads to tropical storms rotating clockwise in the southern hemisphere and anticlockwise in the northern hemisphere.These storms tend to grow in strength as they move across the ocean and lose it as they pass over land (this is not completely true: many tropical storms peter out without reaching land due to wider atmospheric patterns), since the land tends to absorb solar energy while the sea reflects it.

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Magnitude 5.6 Earthquake in the Andaman Islands.

The United States Geological Survey recorded a Magnitude 5.6 Earthquake at a depth of 69.4 km roughly 25 km to the east of Andaman Island, slightly before 8.10 am local time (slightly before 2.40 am GMT) on Tuesday 13 February 2018. There are no reports of any damage or injuries associated with this event, though it was felt on Andaman Island. 

The approximate location of the 13 February 2018 Andaman Earthquake. USGS.

The Andaman Islands sit on the Burma (or Burmese) Plate, a small tectonic plate which underlies part of the eastern Indian Ocean and the western part of Sumatra. To the west of the Andaman Islands this plate is being subducted beneath the Indian Plate, but to the east the situation is more complex. The Burma Plate is being pushed northward relative to the Eurasia and the Sunda Plate (which underlies eastern Sumatra, Java, southern Southeast Asia, most of Borneo and the western Philippines) by the northward movement of the Indian Plate. There is also an area of seafloor spreading beneath the Andaman Sea (separating the Andaman Islands from Southeast Asia), which in turn causes stresses within the Burma Plate, leading to a zone of faulting upon which the Andaman Islands are situated.

(Left) The movement of the Burma and surrounding plates. Sheth et al. (2011) (Right) Tectonic stresses within and around the Burma Plate. Renjith (2013).

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.

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Neenchelys andamanensis: A new species of Worm Eel from the Andaman Sea.

Worm Eels of the genus Neenchelys are small burrowing Eels found in the Indian ans Pacific Oceans. There are currently about ten described species, with other undescribed species known in museum and university collections.

In a paper published in the journal Zootaxa on 24 December 2015, Yusuke Hibino of the Fisheries Research Laboratory at Mie University, Ukkrit Satapoomin of the Phuket Marine Biological Center and Seishi Kimura, also of the Fisheries Research Laboratory describe a new species of Worm Eel from the Andaman Sea.

The new species is named Neenchelys andamanensis, meaning 'from the Andaman'. It is described from a single specimen collected from a depth of between 520 and 531 m off the coast of Phucket in 1999, and held in the collection of the Phuket Marine Biological Center. The specimen is 336 mm in length, and is of uncertain sex. It can be differentiated from other species in the same genus by the number of ribs and tail vertebrae.

Neenchelys andamanensis, 336 mm TL, Andaman Sea. (A) position of anus, (D) origin of dorsal fin. Hibino et al. (2015).

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Neenchelys gracilis: A new species of Worm Eel from Taiwan.                                         Worm Eels, Ophichthidae, are burrowing Eels found...

Japanese Eel classified as Endangered.        The International Union for the Conservation of Nature published its annual update of its Red List of Threatened Species on Thursday 12 June 2014, marking the 50th year of the list's existence, and revising the status of a number of Plant and Animal species from around...

The effect of parasitic Nematodes on European Eels.                                       European Eels, Anguilla anguilla, have a complex life-cycle; they hatch from eggs in the Sargasso Sea...

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The age of Barren Island.

Barren Island is an uninhabited volcanic island belonging officially to India's Andaman Islands (making it India's only active volcano), though it is about 100 km to the east of the main Andaman Island group and about 450 km west of the coast of southern Myanmar. The island is about 3 km in diameter and rises 354 m above sea level. It is the only active volcano in the region, though it forms part of a group with a number of dormant volcanoes including Narcondam Island and Alcock and Sewell seamounts.

Satelite image of an eruption on the Barren Island volcano captured by NASA's Earth Observing 1 satellite on 25 September 2010. Earth Observatory.

The volcanoes sit on the Burma (or Burmese) Plate, a small tectonic plate underlying the Andaman Islands, part of the eastern Indian Ocean and the western part of Sumatra. To the west of the Andaman Islands this plate is being subducted beneath the Indian Plate, but to the east the situation is more complex. The Burma Plate is being pushed northward relative to the Eurasia and the Sunda Plate (which underlies eastern Sumatra, Java, southern Southeast Asia, most of Borneo and the western Philippines) by the northward movement of the Indian Plate, but there is an area of seafloor spreading beneath the Andaman Sea (separating the Andaman Islands from Southeast Asia), which in turn causes stresses within the Burma Plate, leading to a zone of faulting upon which the volcanic islands and seamounts are situated.

In 1991 Barren Island began erupting after 159 years of dormancy. As an active volcano in the Anderman Sea it presents a direct potential threat to settlements in the Anderman and Nicobar Islands, and potentially the nations of Southeast Asia, as well as a tsunami risk to nations around the Indian Ocean, and a threat to aviation, making an understanding of the eruptive history of the volcano a priority for Indian vulcanologists. Previous studies have revealed a series of seven ash and tephra (volcanic material) layers on the island, the oldest of which dates back to 70 000 years ago, although the island and its volcano are thought to be somewhat older.

In a paper published in the journal Currant Science on 10 April 2013, Jyotiranjan Ray of the Physical Research Laboratory, Kanchan Pande of the Department of Earth Sciences at the Indian Institute of Technology Bombay and Neeraj Awasthi, also of the Physical Research Laboratory, describe the results of an Argon-Argon isotope study of minerals from tephra close to Barren Island.

Argon-Argon dating relies on determining the ratio of radioactive Argon⁴⁰ to non-radioactive Argon³⁹ within minerals from igneous or metamorphic rock (in this case volcanic ash) to determine how long ago the mineral cooled sufficiently to crystalize. The ratio of Argon⁴⁰ to Argon³⁹ is constant in the atmosphere, and this ratio will be preserved in a mineral at the time of crystallization. No further Argon³⁹ will enter the mineral from this point, but Argon⁴⁰ is produced by the decay of radioactive Potassium⁴⁰, and increases in the mineral at a steady rate, providing a clock which can be used to date the mineral.

Ray et al. studied plagioclase grains (plagioclase is a common mineral in volcanic rocks) from two tephra layers, previously dated to no more than 61 000 years old. They obtained dates of around 1.8 million years for the minerals. They infer that the minerals were formed within the volcano at around this time, and ejected around 61 000 years ago (this is not unusual for volcanos). From this they conclude that active volcanism has been occurring on the Barren Island volcano for at least 1.8 million years (though the island itself is not necessarily this old.

Backscattered X-ray images of two typical lithic clasts. Mineral grains (phenocrysts) and vesicular matrix are marked. Plag, Plagioclase; T-Mt, Titaniferous magnetite; Ol, Olivine; Cpx, Clino-pyroxene. Ray et al. (2013).

See also...

 Eruption on Mount Sinabung.

 Dating the Toba Eruption.

 Eruptions on Barren Island.

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Eruptions on Barren Island.

NASA's MODIS (Moderate Resolution Imaging Spectroradiometer) system, mounted on the Terra (EOS AM) and Aqua (EOS PM) satellites, detected a hotspot developing over the Baren Island Volcano in the Andaman Islands over the period 10-16 October 2013. On 15 October an image taken at visual wavelengths by the Terra Satellite appeared to show a volcanic plume over the island, and the Indian Navy confirmed that a surveillance plane had spotted smoke and lava on the island. On 17 October the Darwin Volcanic Ash Advisory Center issued a warning to aviation of an ash column rising 3.6 km above the island and drifting to the northwest.

A previous eruption on Barren Island. Wikimapia.

Barren Island is an uninhabited volcanic island belonging officially to India's Andaman Islands (making it India's only active volcano), though it is about 100 km to the east of the main Andaman Island group and about 450 km west of the coast of southern Myanmar. The island is about 3 km in diameter and rises 354 m above sea level. It is the only active volcano in the region, though it forms part of a group with a number of dormant volcanoes including Narcondam Island and Alcock and Sewell seamounts.

The approximate location of Barren Island. Google Maps.

The volcanoes sit on the Burma (or Burmese) Plate, a small tectonic plate underlying the Andaman Islands, part of the eastern Indian Ocean and the western part of Sumatra. To the west of the Andaman Islands this plate is being subducted beneath the Indian Plate, but to the east the situation is more complex. The Burma Plate is being pushed northward relative to the Eurasia and the Sunda Plate (which underlies eastern Sumatra, Java, southern Southeast Asia, most of Borneo and the western Philippines) by the northward movement of the Indian Plate, but there is an area of seafloor spreading beneath the Andaman Sea (separating the Andaman Islands from Southeast Asia), which in turn causes stresses within the Burma Plate, leading to a zone of faulting upon which the volcanic islands and seamounts are situated.

The movement of the Burma and surrounding plates. Sheth et al. (2011).

Tectonic stresses within and around the Burma Plate. Renjith (2013).

See also Two significant Earthquakes in Sagaing Region, northern Myanmar, Magnitude 5.0 Earthquake in northern Myanmar, Magnitude 4.5 Earthquake in northwest Myanmar, Magnitude 6.1 Earthquake kills at least twelve people in northwest Sumatra and Eruption on Mount Marapi, Sumatra.

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