Sciency Thoughts: Shikoku Island

Showing posts with label Shikoku Island. Show all posts

Saturday, 7 July 2018

Fifteen known deaths as floods and landslides hit Japan.

Fifteen people are known to have died around 50 are missing and over 210 000 more have been forced to evacuate their homes as a series of landslides and floods swept across southwestern Japan this week. At least one person has died in a landslide in Okayama Prefecture, on southwestern Honshū Island, while in neighbouring Hiroshima Prefecture two people have died, one due to another landslide and the second a child caught in a flood, while five people are still missing after their hose collapsed. In Hyogo Prefecture three construction workers were swept down a storm drain by flooding, though two of these were pulled out alive. In Kyoto Prefecture a 52-year-old woman is reported to have died, though details of this incident have not yet been released. In Ehime Prefecture on Shikoku Island, a woman has been found dead after her house was hit by a landslide. Evacuation orders are in place for parts of Ibari, Osaka, Kobe, and Gifu prefectures.

A train derailed by a landslide in Saga Prefecture, Japan, earlier this week. STR/AFP/Getty Image.

Many areas of east and south Asia have been hit by exceptional rainfall this year, leading to a string of fatalities in flood and landslide events. Until now Japan has been relatively unaffected, but this week, Typhoon Prapiroon, which passed through the sea of Japan earlier this braining high rainfall with it, with as much as 400 mm of rain falling in a single day in some areas. 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. Parts of Japan are currently considered to be at a higher risk of landslides due to a Magnitude 6.1 Earthquake in Kobe Prefecture last month, which weekend both man-made and geological structures in the region.

Road blocked by a landslide in Gifu Prefecture, Japan, on 4 July 2018. Gifu Prefectural Government.

Gifu Prefectural Government

Tropical storms (called Typhoons in the West Pacific and Indian Oceans) 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.

Floodwaters in Hiroshima City on Saturday 7 July 2018. Kyodo News.

The low pressure above tropical storms causes water to rise there by ~1 cm for every millibar drop in pressure, leading to a storm surge that can overwhelm low-lying coastal areas, while at the same time the heat leads to high levels of evaporation from the sea - and subsequently high levels of rainfall. This can cause additional flooding on land, as well as landslides.

Sunday, 25 March 2018

Phyllocnistis indistincta, Phyllocnistis saepta & Phyllocnistis verae: Three new species of Leaf-mining Moths from Asia.

Moths of the Family Gracillariidae are found throughout the world except on Antarctica and some remote islands. Their larvae are leaf-miners, worm-like caterpillars that live in tunnels inside leaves. Some groups of Gracillarid Moths are specialist miners of the leaves of some of the most ancient groups of Angiosperms (flowering plants) such as Laurels and Magnolias, and fossils leaf mines that resemble those of the Moths have been found in fossilised leaves from the Cretaceous of North America, which also suggests this is an ancient association. However the oldest fossils of the Moths themselves are from (Eocene) Baltic amber, and there is no way to connect these moths to the leaf mines, so it is quite conceivable that the Moths have only recently colonised these plants, and that the burrow shape is coincidental, simply a good shape for a leaf mine in this sort of leaf.

In a paper published in the journal ZooKeys on 18 February 2018, Natalia Kirichenko of the Sukachev Institute of Forest, the Siberian Federal University, and Zoologie Forestière, Paolo Triberti of the Museo Civico di Storia Naturale in Verona, Shigeki Kobayashi of the Entomological Laboratory at Osaka Prefecture University, Toshiya Hirowatari of the Entomological Laboratory at Kyushu University, Camiel Doorenweerd of the Department of Plant and Environmental Protection Sciences at the University of Hawai'i, and the Naturalis Biodiversity Centre, Issei Ohshima of the Department of Life and Environmental Sciences at the Kyoto Prefectural University, Guo-Hua Huang of the Hunan Provincial Key Laboratory for Biology and Control of Plant Diseases and Insect Pests at the Hunan Agricultural University, Min Wang of the Department of Entomology at the South China Agricultural University, Emmanuelle Magnoux, also of Zoologie Forestière, and Carlos Lopez-Vaamonde, again of Zoologie Forestière, and of the Institut de Recherche sur la Biologie de l’Insecte at the Université François-Rabelais de Tours, describe three new species of Leaf-mining Moths from Dogwood trees, Cornus sp., in Asia. All are placed in the genus Phyllocnistis.

The first new species is named Phyllocnistis indistincta, in reference to the colouration of the forewing, with indistinct yellow-white bands. This species has wing-spans of between 4.0 and 6.5 mm, and is white in colour with yellow, orange, brown and black markings. It was found on Wedding Cake Trees (Cornus controversa), Flowering Dogwoods (Cornus florida), and Korean Dogwoods (Cornus kousa), on Honshu, Shikoku and Kyushu islands, Japan.

Phyllocnistis indistincta, male specimen. Scale bar is 1 mm. Kirichenko et al. (2018).

The second new species described is named Phyllocnistis verae, in honour of Vera Kirichenko, the mother of Natalia Kirichenko. This species has wingspans of 6.0-6.1 mm and is white with dark brown and orange markings. This species was found at a single location, beside the Yenisei River in Krasnoyarsk Krai, Siberia, on a White Dogwood tree, Cornus alba.

Phyllocnistis verae, male specimen. Scale bar is 1 mm. Kirichenko et al. (2018).

The final new species is named Phyllocnistis saepta, meaning 'to block' in reference to the shape of a blotch on the forewing. This species has a wingspan of 5.0 mm and is white in colour with orange, brown and black markings. This species was found living at a single location in Weixi County, in Yunnan Province, China, on a Large-leaf Dogwood, Cornus macrophylla.

Phyllocnistis saepta, male specimen. Scale bar is 1 mm. Kirichenko et al. (2018).

Tuesday, 13 September 2016

Borniopsis mortoni: A new species of Galeommatoid Bivalve from Shikoku Island, Japan.

Galeommatoid Bivalves are an extremely diverse group of bivalves from shallow and intertidal waters around the world. They are noted for the commensual relationships that many species form with other invertebrates, living either on the bodies of their partners or within their burrows. Members of the genus Borniopsis are known from around the coast of eastern Asia, where they have been found living on the bodies of Mantis Shrimps, Crabs, Holothurians (Sea Cucumbers), Sipunculid Worms, Echiurans (Spoon Worms) and probably Tanaid Crustaceans.

In a paper published in the journal ZooKeys on 7 September 2016 Ryutaro Goto of the Museum of Zoology and Department of Ecology and Evolutionary Biology at the University of Michigan and Hiroshi Ishikawa of Uwajima on Shikoku Island, Japan, describe a new species of Borniopsis from Sea Cucmbers found on mud flats at the mouth of the Souzu River on southwestern Shikoku Island.

The new species is named Borniopsis mortoni, in honour of Brian Morton of the Univeristy of Hong Kong for his contributions to marine biology, marine ecology and malacology, including the discovery of many Galeommatoid species. Borniopsis mortoni was found living on the bodies of the Sea Cucumber Patinapta ooplax, a Worm-like burrowing species, with about 70% of the Sea Cucumbers inspected hosting the bivalves and some having more than ten attached.

Patinapta ooplax with multiple individuals of Boriopsis mortoni attached. Goto & Ishikawa (2016).

The Bivalves are small, with the largest specimens reaching 4.1 mm by 2.8 mm, and have thin, elongate and slightly inflated shells. The periostracum (covering of the shell) is tan to brown, withblack markings. They attach to their hosts using both their foot and byssal threads (thick silky threads produced by some Bivalves as a way of attaching themselves to substrates).

A crawling individual of Boriopsis mortoni. Goto & Ishikawa (2016).