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Australia from Space: Part 4

MORE WONDERFUL IMAGES of Australia’s coastline, courtesy of the European Envisat Earth-monitoring satellite. Envisat was launched in March 2002 and at 8.5-tonnes is one of the largest satellites ever put into orbit. It circles the Earth every 101 minutes from north to south.

Satellite image of the Great Barrier Reef

An Envisat MERIS image of the Great Barrier Reef centred on Cape York Peninsula. Taken on 19 August 2004, this MERIS Full Resolution mode images has a spatial resolution of 300 metres.

Satellite image of the Southern Great Barrier Reef

This Envisat image features the southern part of the Great Barrier Reef off Australia’s Queensland coast. It is the world’s most protected marine area, one of its natural wonders and a World Heritage site. Spanning more than 2,000 km and covering an area of some 350,000 sq km, it is the largest living structure on Earth and the only one visible from space. This image was acquired by Envisat’s Medium Resolution Imaging Spectrometer (MERIS) on 8 November 2010 at a resolution of 300 metres

Satellite image of the Northern Great Barrier Reef

Another view of the Great Barrier Reef. Australian researchers have discovered that Envisat's Medium Resolution Imaging Spectrometer (MERIS) sensor can detect coral bleaching down to 10 metres depth. This means Envisat could potentially map coral bleaching on a global scale. MERIS acquired this image on 18 May 2008, working in Full Resolution mode to yield a spatial resolution of 300 metres.

Close up of the sea off northwestern WA

Sea and coral atolls off the West Australian coast, as seen by Envisat's MERIS ocean colour sensor.

Earlier Australia from Space pictorials:

Australia from Space: Part 1

Australia from Space: Part 2

Australia from Space: Part 3

Adapted from information issued by ESA.

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Tuvalu: Islands in Danger

Satellite image of Tuvalu

The world's fourth-smallest nation, Tuvalu, comprises four coral reefs and five atolls, located about 1,000 km north of Fiji in the South Pacific.

Funafuti Atoll in the Tuvalu Islands (formally known as the Ellice Islands), is a coral-reef lagoon 25 km north-to-south, 18 km east-to-west, and surrounded by small islets.

Tuvalu comprises four coral reefs and five atolls, located about 1,000 km north of Fiji in the South Pacific. With an area of 26 square kilometres, it is the fourth smallest country in the world, larger only than Vatican City, Monaco, and Nauru in the Pacific Ocean.

The Ellice Islands became a British protectorate in 1892 together with the Gilbert Islands (a part of the Republic of Kiribati) to the north-northwest, and became a colony in 1915.

The main inhabitants of Tuvalu are Polynesian and those of the Gilbert Islands are Micronesian; therefore, the two islands dissociated in 1975. They achieved independence in 1978 and became members of the Commonwealth of Nations.

The capital, Funafuti, is located at the easternmost bend (right) of the atoll and it possesses the only airport in Tuvalu, the airstrip of which is slightly wider than a road and has no lighting or guidance lights. Air Pacific operates two flights per week between it and Suva, the capital of Fiji.

Satellite image close-up of Funafuti

Close-up of Funafuti, the capital of Tuvalu. The nation's only airstrip can be seen as a thin white line running diagonally. It doubles as a playground and football field.

Since this airstrip is the only open space in the atoll, it is also used as a playground and a football field by the people.

The name Tuvalu consists of Tu, meaning “consist of,” and Valu, meaning “eight.” Thus, it means “a country consisting of eight islands” in the Tuvaluan language.

At the beginning of their independence in 1978, Tuvalu was composed of eight inhabited small islands. Later people moved to an uninhabited islet called Niulakita. Therefore, the new design of the national flag now has nine stars reflecting the number of islands. The name of the nation, however, has not been changed.

The population of the Tuvalu Islands is about 10,000. Rain is the main source of water. Since Tuvalu has almost no natural resources, much of the government revenue depends on overseas remittances from emigrant mariners. The substantial budget deficit is covered by the investment return of the Tuvalu Trust Fund, which was established in 1978 by Australia, the United Kingdom, New Zealand, and Tuvalu. Payment from the US government according to the treaty on fisheries and the sale of Tuvalu’s Internet domain name “.tv” are other sources of income.

As a result of rising sea levels, like the Republic of Kiribati (South Pacific) and Maldives (Indian Ocean), Tuvalu is also in danger of submerging. Water gushes out from the ground, and houses and roads are flooded during high tide. Spring water from dents that were made during construction of the airfield, lowlands where people tend to live, and contaminated wastewater dramatically decreasing foraminifers, which are responsible for forming sands, are suspected as the causes of this phenomenon.

However, in Tuvalu, since the highest point is only 4.5 metres above sea level, it is a land easily affected by rises in the sea level. The nation has already begun evacuating some of its residents to New Zealand. Japan is cooperating in coastal protection, disaster prevention, and developing alternative energy sources.

The image was made by the Japan Aerospace Exploration agency Advanced Land Observing Satellite (ALOS), also known as “Daichi”.

Adapted from information issued by JAXA.

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