Hurricane Eta exposes nineteenth century shipwreck on the coast of Florida.

Hurricane Eta swept across central Florida on 12 November 2020, causing eleven fatalities, in addition to the 178 it had already claimed in Central America, in addition to causing widespread flooding and causing about a billion dollars' worth of damage to property. After the storm had passed it was discovered that high tides brought on by the hurricane's storm surge had scoured the beach at the Fort Matanzas National Monument in St John's County on the east coast of Florida, exposing the remains of a ship that had been burried by the sand. 

 

Exposed timbers on the foreshore at Fort Matanzas National Monument, believed to have come from an nineteenth century shipwreck. CNN.

The site is now being investigated archaeologists from the St. Augustine Lighthouse Archaeological Maritime Program and students from Flagler College, who have determined that the remains probably belong to the Caroline Eddy, an American merchant ship which sank in the area on 29 August 1880, after becoming caught in a storm.

 

Chuck Meide of the St. Augustine Lighthouse Archaeological Maritime Program examaning timbers believed to have come from the Caroline Eddy, a merchant ship which sank off the coast of Florida in August 1880. St Augustine.

Tropical storms, known as hurricanes in the Caribbean, 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 inrushing 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.

 

The formation of a tropical cyclone. Natural Disaster Management.

Despite the obvious danger of winds of this speed, which can physically blow people, and other large objects, away as well as damaging buildings and uprooting trees, the real danger from these storms comes from the flooding they bring. Each drop millibar drop in air-pressure leads to an approximate 1 cm rise in sea level, with big tropical storms capable of causing a storm surge of several meters. This is always accompanied by heavy rainfall, since warm air over the ocean leads to evaporation of sea water, which is then carried with the storm. These combined often lead to catastrophic flooding in areas hit by tropical storms. 

 

The formation and impact of a storm surge. eSchoolToday.

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At least eight dead after Typhoon Wutip hits Vietnam.

Typhoon Wutip made landfall in central Vietnam on Monday 30 September 2013, brining with it high winds and widespread flooding. Over 300 mm of rain fell within 24 hours in parts of the country. The known death toll in the country currently stands at eight, with over 200 injured, though local authorities fear that this will rise further. Over 200 000 homes are understood to have been either destroyed by the typhoon, or submerged by flooding, and there has been extensive damage to the country's power and communication systems. Large areas of farmland are understood to have been inundated, causing extensive damage to crops and considerable loss of livestock.

Damage caused by Typhoon Wutip in central Vietnam. APP.

Chinese authorities are still searching for 58 missing fishermen from a fleet of vessels that encountered the storm near the Paracel Islands in the South China Sea on 29 September, sinking at least two vessels.  The storm has also brought widespread flooding to Laos, Cambodia and Thailand. 

A life-raft from the fishing vessel Yuetaiyu 62116 which sank in the South China Sea after encountering Typhoon Wutip on 29 September 2013. Xinhua.

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 inrushing 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.

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, which are 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.

A home destroyed by Typhoon Wutip in central Vietnam. Vietnam Investment Review.

See also Around 75 missing as Typhoon Wutip sinks Chinese fishing vessels, Typhoon Usagi kills at least 25 in Guangdong Province, China, One person confirmed dead and two more missing as Typhoon Man-yi hits Japan, Three dead as Tropical Storm Kong-Rey batters Taiwan and Widespread flooding as Typhoon Trami hits Fujian Province, China.

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Around 75 missing as Typhoon Wutip sinks Chinese fishing vessels.

Two Chinese fishing vessels are known to have sunk and a third is missing after they encountered high winds associated with Typhoon Wutip close to the Paracel islands, around 330 km south of the Chinese island of Hainan, on Sunday 29 September 2013. The ships were part of a fleet of five vessels with a combined crew of about 150 people. A rescue attempt is underway, but only 14 survivors have been found so far. Typhoon Wutip was a Category 2 storm, with sustained winds of over 96 km per hour, though it has lost some energy as it moves towards landfall in Vietnam.

The approximate location of the area where the Chinese vessels were lost. Google Maps.

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 inrushing 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.

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, which are 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.

See also Typhoon Usagi kills at least 25 in Guangdong Province, China, One person confirmed dead and two more missing as Typhoon Man-yi hits Japan, Three dead as Tropical Storm Kong-Rey batters Taiwan, Widespread flooding as Typhoon Trami hits Fujian Province, China and Typhoon Utor hits south China.

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A new species of Thecideide Brachiopod from a shipwreck off the coast of Sulawesi.

Brachiopods (or Lampshells) superficially resemble Bivalve Molluscs, though they are not closely related. They were abundant in the seas of the Palaeozoic, often dominating benthic faunas, but today are comparatively rare, and seldom seem outside the tropics. Brachiopods have a filter feeding apparatus called a lophophore, unlike anything found in any Mollusc, but also found in Bryozoans and Phoronid Worms. This is encased with in a shell with two valves, each symmetrical about a midline, but not necessarily the same as each other, along with the rest of the organs of the body; there is typically remarkably little flesh to a Brachiopod compared to a Mollusc with a shell the same size. Thecideide Brachiopods are a group of small Articulate Brachiopods (Brachiopods in which the shell has a toothed hinge, as opposed to Inarticulate Brachiopods, which have shells held together by muscle and tendons) which appeared in the Triassic and are common (for Brachiopods) today. They cement their ventral valves to hard substrates, such as rocks or the shells of other organisms, and prefer cryptic (hidden) environments.

In a paper published in the journal Zootaxa on 7 August 2013, Eric Simon of the Department of Palaeontology at the Belgian Royal Institute for Natural Sciences and Jana Hoffmann of the Museum für Naturkunde at the Leibniz-Institut für Evolutions- und Biodiversitätsforschung, describe a new species of Thecideide Brachiopod from a shipwreck in the harbour of Donggala, Central Sulawesi, Indonesia.

The new species is placed in the genus Ospreyella, and given the specific name mutiara, which means 'pearl' in Indonesian, and is the name of the wrecked ship in which the species was discovered. Ospreyella mutiara is a small-to-medium sized Thecideide Brachiopod reaching at most 4 mm. The females are larger than the males and have a distinct marsupial notch (used to hold a brood pouch in which the young, attached to specialized tentacles, are nursed prior to dispersal). The shells are whitish and biconvex.

Ospreyella mutiara. (1) Fully grown adult  attached to the substrate in (a) dorsal, (b) ventral and (c) lateral views. (2) Young specimen attached to the substrate in (a) dorsal, (b) anterior and (c) lateral views. (3) A piece of metallic substrate from the store in the shipwreck with several juvenile specimens; (a) overview, (b) detailed view of two juvenile specimens attached to the substrate and (c) detailed view of one juvenile specimen. (4) Adult specimen with a median brood pouch and larvae. (a) Opened complete articulated specimen showing the lophophore in living position. Specialized tentacles are located at the posterior part of the lophophore. (b) Dorsal view of ventral valve showing detached fibres of the adductor and diductor muscles in the posterior part of the specimen. Two calcitic oval pads cover the gonads in the visceral cavity. Exposed larvae are visible between the calcitic pads in the posterior part of the valve. (5) Adult ventral valve attached to the substrate. The two calcitic oval pads covering the gonads are missing. (a) Dorsal view showing the peripheral ridge, the surface of the valve floor, the interarea, the pseudodeltidium and one tooth. The left tooth is broken. (b) Detailed view of the hemispondylium which consists of two pointed lateral lobes and a prominent median myophragm. (6) Juvenile ventral valve attached to the substrate. The sculptured surface of the anterior part of the pseudodeltidium is very apparent. The ventral valve is coalesced with the substrate. (7) Dorsal view of the posterior part of the ventral valve. The interarea exhibits fine sub-parallel growth lines. The pseudodeltidium is convex. The hinge line is straight. The prominent protegulum exhibits a wrinkled surface. (8) Dorsal view of the pseudodeltidium and the hinge line of the ventral valve. Simon & Hoffmann (2013).

Ospreyella mutiara. (1) Very early juvenile stage with a trocholophe lophophore possessing 27 tentacles. Lateral adductor and median adductor muscles visible on the left side of the shell. (2) Early juvenile stage with a schizolophe lophophore possessing 48 tentacles. The median ramus precursor is developed. (3) Juvenile with schizolophe lophophore consisting of 55 tentacles. The median ramus is widening. Detached lateral adductor and median adductor muscle fibres are visible. (4) Developmental stage with ptycholophe lophophore. Detached lateral adductor and median adductor muscle fibres are visible. (5) Specimen considered as “male” with further developed median ramus and ramuli. A marsupial notch is missing. (6) One of the largest specimens with male features. No marsupial notch is apparent. (a) Ventral view, (b) anterior view, (c) lateral view, (d) posterior view and (e) detailed view of the entire median portion of the brachial bridge. (7) One of the smallest specimens with female features. This specimen considered as “female” possesses a brooding apparatus. Two larvae are attached to the specialized tentacles, which are removed from the median brood pouch in the ventral valve. (a) Ventral view. The median ramus and the ramuli are further developed than in the largest shell with male features. (b) Detailed view of the larvae attached to the specialized tentacles. Fragments of the broken brood pouch are still covering the larvae. (8) Specimen with female features. Three larvae are attached to the specialized tentacles. The median ramus and the ramuli are well developed. (a) Ventral view. (b) Detailed view of the marsupial notch with specialized tentacles and attached larvae. (9) A larger specimen with female features. Marsupial notch and specialized tentacles are present. No larvae are attached to the tip of the tentacles. The tentacles of the lophophore are perfectly spaced by spines on top of the major interbrachial lobe. (a) Ventral view, (b) lateral view, (c) anterior view and (d) posterior view. (10) Fully grown specimen with female features. The median ramus is uplifted and exhibits a very narrow concave crest. The anterior median depression is inconspicuous. (a) Ventral view. (b) Detailed anterior view of the marsupial notch with specialized tentacles. (c) Detailed posterior view of the marsupial notch with specialized tentacles. Simon & Hoffmann (2013).

The specimens were collected from within a shipwreck in 30 m of water at the entrance to the harbour of Donggala in Central Sulawesi, Indonesia. The ship sank 58 years ago and its interior is extremey dark, resembling a cave, which suggests that submarine caves might be the natural habitat of Ospreyella mutiara. This is the first time a member of the genus Ospreyella has been found in Indonesia, however the discovery is not altogether surprising as the genus in known from both the Indian and Pacific Oceans.

The location of the shipwreck of the Mutaria, where the Brachiopods were collected.

See also Soft tissue preservation in Linguloid Brachiopods from the Early Ordovician Fenxiang Formation of Hubei Province, China.

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