TheTimor Sea (Indonesian:Laut Timor,Portuguese:Mar de Timor,Tetum:Tasi Mane orTasi Timór) is a relatively shallow sea in theIndian Ocean bounded to the north by the island ofTimor withTimor-Leste to the north,Indonesia to the northwest,Arafura Sea to the east, and to the south byAustralia. TheSunda Trench marks the deepest point of the Timor Sea with a depth of more than 3300 metres, separating the continents ofOceania in the southeast andAsia to the northwest and north. The Timor sea is prone to earthquakes and tsunamis north of theSunda Trench, due to its location on theRing of Fire as well as volcanic activity and can experience major cyclones, due to the proximity from theEquator.
The sea contains a number of reefs, uninhabited islands and significanthydrocarbon reserves. International disputes emerged after the reserves were discovered resulting in the signing of theTimor Sea Treaty.
It is possible that Australia's first inhabitants crossed the Timor Sea from theMalay Archipelago at a time when sea levels were lower.[citation needed]
The Timor Sea is named afterTimor, the island on the other side of the sea's northern coastline.[2] The island's name is a variant oftimur,Malay for "east".
The waters to the east are known as theArafura Sea. The Timor Sea is adjacent to three substantial inlets on the north Australian coast, theJoseph Bonaparte Gulf,Beagle Gulf and theVan Diemen Gulf. The Australian city ofDarwin which is located in part on the shore of the Beagle Gulf, is the nearest large city to the sea.[4] The small town ofWyndham is located on the west arm ofCambridge Gulf, an inlet of Joseph Bonaparte Gulf.
The sea is about 480 km (300 mi) wide, covering an area of about 610 thousand km2 (240,000 sq mi). Its deepest point is theTimor Trough (which some geologists consider to be the south-eastern extension of theJava Trench, but others view it as a foreland trough to the Timor Island "mountain range"), located in the northern part of the sea, which reaches a depth of 3,300 m (10,800 ft). The remainder of the sea is much shallower, much of it averaging less than 200 m (660 ft) deep, as it overlies theSahul Shelf, part of the Australiancontinental shelf.
The Big Bank Shoals is an area on the sloping seabed between the continental shelf and the Timor Trough where a number of submerged banks are located.[5] The ecosystem of the shoals differs significantly from the deeper waters surrounding them. In May 2010, it was announced that a crater about 50 km (31 mi) wide has been discovered on the seabed of the Timor Sea.[6]
On the North The Southeastern limit of theSavu Sea [By a line from the Southwest point ofTimor to the Northeast point ofRoti, through this island to its Southwest point] the Southeastern coast of Timor and the Southern limit of theBanda Sea [A line from Tanjong Aro Oesoe, through Sermata to Tanjong Njadora the Southeast point of Lakov (8°16′S128°14′E / 8.267°S 128.233°E /-8.267; 128.233) along the South coasts of Lakov, Moa andLeti Islands to Tanjong Toet Pateh, the West point of Leti, thence a line to Tanjong Sewirawa the Eastern extremity of Timor].
On the East. The Western [limit] of theArafura Sea [A line from Cape Don to Tanjong Aro Oesoe, the Southern point of Selaroe (Tanimbar Islands)].
Many tropical storms andcyclones originate or pass through the Timor Sea. In February 2005, Tropical Cyclone Vivienne disrupted oil and gas production facilities in the area, and the next month, Severe Tropical Cyclone Willy interrupted production.[citation needed] Petroleum production facilities are designed to withstand the effects of cyclones, although as a safety precaution production work is often reduced or temporarily halted and workers evacuated by helicopter to the mainland – usually to Darwin orDili.
August 2005 NASA satellite photograph of theRowley Shoals
A number of significant islands are located in the sea, notablyMelville Island, part of theTiwi Islands, off Australia and the Australian-governedAshmore and Cartier Islands. It is thought that early humans reached Australia by "island-hopping" across the Timor Sea.
The Timor Current is an oceanic current that runs south-west in the Timor Sea between the Malay Archipelago and Australia. It is a major contributor to theIndonesian Throughflow that transports water from thePacific Ocean to theIndian Ocean.
Oil slick from theMontara oil spill in the Timor Sea September 2009.Big John
Beneath the Timor Sea lie considerable reserves ofoil andgas. Confirmation of the prospectivity of the Timor Sea came when Woodside-Burmah's Big John rig drilled Troubadour No. 1 well in June 1974 on the Troubadour Shoals about 200 kilometres (120 mi) southeast of Timor, and intersected 83 metres (272 ft) of hydrocarbons. A number of offshore petroleum projects are in operation and there is considerable exploration activity either underway and numerous proposed projects. A gas pipeline crosses the Timor Sea from the Joint Petroleum Development Area toWickham Point near Darwin.[8]
The Timor Sea was the location for Australia's largestoil spill when theMontara oil field leaked oil, natural gas andcondensate from 21 August to 3 November 2009.[9] During the spill 400 barrels (64 m3) of oil leaked each day. The Montara Commission of Inquiry placed blame on the Thai company PTTEP, owner of the wells.[1] In response to the disaster, Indonesian seaweed farmers engaged in a class action lawsuit to claim for damages.[10]
The largest petroleum project in operation in the Timor Sea is theBayu-Undan project operated bySantos.[11] The Bayu-Undan field is located approximately 500 km (310 mi) north-west ofDarwin in theBonaparte Basin.[12] Production commenced in 2004 as a gas recycle project – with liquids (condensate, propane and butane) being stripped from the raw production stream and exported. Gas was pumped back down into the reservoir. At around the same time, construction commenced on a 500 km (310 mi) subseanatural gas pipeline connecting the Bayu-Undan processing facility to aliquefied natural gas plant situated at Wickham Point inDarwin harbour. Since the completion of the pipeline and the Darwin LNG plant in 2005, gas produced offshore at Bayu-Undan is now transported to the Darwin plant where it is converted into a liquid and transported toJapan under long-term sales contracts.[13] Timor-Leste has made, as of 2017, over $18 billion from Bayu-Undan since production began; however, it is predicted its reserves will be exhausted by 2023.[14]
TheIchthys gas field is anatural gas field located in the Timor Sea, off the northwestern coast ofAustralia. The field is located 220 km offshore Western Australia and 820 km southwest of Darwin, with an average water depth of approximately 250 metres.[15] It was discovered in 2000. First Gas from the Ichthys field was achieved on 30 July 2018.[16]
AED Oil owns the large oil project at Puffin oilfield andWoodside Petroleum previously produced oil at theLaminaria oil field. The Greater Sunrisegas field, discovered in 1974, is one of the largest in the area and is expected to earn East Timor several billion dollars in royalty revenues. Woodside Petroleum plans to process gas from Greater Sunrise via afloating platform, howeverXanana Gusmão, East Timor's Prime Minister opposes this plan and instead wants the gas to go toBeaço via apipeline for processing.[17]
Since 2018,Santos has sought to establish the Barossa offshore gas project to exploit a gas field in order to supply the Darwinliquefield natural gas (LNG) onshore terminal when gas fromBayu-Undan runs out in the 2020s. This has been opposed by Dangalaba andLarrakia people as well as climate justice organisations.[10]
Since the discovery of petroleum in the Timor Sea in the 1970s, there have been disputes surrounding the rights to ownership and exploitation of the resources situated in a part of the Timor Sea known as theTimor Gap, which is the area of the Timor Sea which lies outside the territorial boundaries of the nations to the north and south of the Timor Sea.[18] These disagreements initially involved Australia and Indonesia, although a resolution was eventually reached in the form of theTimor Gap Treaty. After declaration of East Timor's nationhood in 1999, the terms of the Timor Gap Treaty were abandoned and negotiations commenced between Australia and East Timor, culminating in theTimor Sea Treaty.
From 1965 to 2018, Australia's territorial claim extended to the bathymetric axis (the line of greatest sea-bed depth) at the Timor Trough. It overlapped East Timor's own territorial claim, which followed the former colonial powerPortugal and theUnited Nations Convention on the Law of the Sea in claiming that the dividing line should be midway between the two countries. In 2018, Australia agreed to a median line boundary.
TheTimor Sea Treaty, which was signed on the 20 May 2002, led to the establishment of the Timor Sea Designated Authority (TSDA). This organisation is responsible for the administration of all petroleum-related activities in a part of the Timor Sea known as the Joint Petroleum Development Area (JPDA). The treaty was ratified in February 2007.[18]
Under the terms of the treaty, royalties on petroleum production in the JPDA are split in a 90:10 ratio betweenEast Timor andAustralia.[19] It has been criticised because the treaty did not finalise themaritime boundary between East Timor and Australia.[18]
TheAustralia–Timor Leste Treaty Establishing Their Maritime Boundaries in the Timor Sea was signed on 6 March 2018 at United Nations headquarters in New York in the presence of United Nations Secretary-General Antonio Guterres.[20]
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