A typhoon is a mature tropical cyclone that develops between 180° and 100°E in the Northern Hemisphere. This region is referred to as the Northwestern Pacific Basin, is the most active tropical cyclone basin on Earth, accounting for one-third of the world's annual tropical cyclones. For organizational purposes, the northern Pacific Ocean is divided into three regions: the eastern and western; the Regional Specialized Meteorological Center for tropical cyclone forecasts is in Japan, with other tropical cyclone warning centers for the northwest Pacific in Hawaii, the Philippines and Hong Kong. While the RSMC names each system, the main name list itself is coordinated among 18 countries that have territories threatened by typhoons each year A hurricane is a storm that occurs in the Atlantic Ocean or the northeastern Pacific Ocean, a typhoon occurs in the northwestern Pacific Ocean, a tropical cyclone occurs in the South Pacific or the Indian Ocean. Within the northwestern Pacific, there are no official typhoon seasons as tropical cyclones form throughout the year.
Like any tropical cyclone, there are a few main requirements for typhoon formation and development: sufficiently warm sea surface temperatures, atmospheric instability, high humidity in the lower to middle levels of the troposphere, enough Coriolis effect to develop a low pressure center, a pre-existing low level focus or disturbance, a low vertical wind shear. While the majority of storms form between June and November, a few storms do occur between December and May. On average, the northwestern Pacific features the most numerous and intense tropical cyclones globally. Like other basins, they are steered by the subtropical ridge towards the west or northwest, with some systems recurving near and east of Japan; the Philippines receive the brunt of the landfalls, with China and Japan being impacted less. Some of the deadliest typhoons in history have struck China. Southern China has the longest record of typhoon impacts for the region, with a thousand-year sample via documents within their archives.
Taiwan has received the wettest known typhoon on record for the northwest Pacific tropical cyclone basins. The term typhoon is the regional name in the northwest Pacific for a severe tropical cyclone, whereas hurricane is the regional term in the northeast Pacific and northern Atlantic. Elsewhere this is called severe tropical cyclone, or severe cyclonic storm; the Oxford English Dictionary cites Urdu ṭūfān and Chinese tai fung giving rise to several early forms in English. The earliest forms -- "touffon" "tufan", "tuffon", others—derive from Urdu ṭūfān, with citations as early as 1588. From 1699 appears "tuffoon" "tiffoon", derived from Chinese with spelling influenced by the older Urdu-derived forms; the modern spelling "typhoon" dates to 1820, preceded by "tay-fun" in 1771 and "ty-foong", all derived from the Chinese tai fung. The Urdu source word توفان ṭūfān comes from the Persian (Persian: توفان/طوفان tūfān meaning "storm" which comes from the verb (Persian: توفیدن/طوفیدن tūfīdan; the word طوفان is derived from Arabic as coming from ṭāfa, to turn round.
The Chinese source is the word tai taifeng. The modern Japanese word, 台風, is derived from Chinese; the first character is used to mean "pedestal" or "stand", but is a simplification of the older Chinese character 颱, which means "typhoon". The Ancient Greek Τυφῶν has secondarily contaminated the word; the Persian term may have been influenced by the Greek word. A tropical depression is the lowest category that the Japan Meteorological Agency uses and is the term used for a tropical system that has wind speeds not exceeding 33 knots. A tropical depression is upgraded to a tropical storm should its sustained wind speeds exceed 34 knots. Tropical storms receive official names from RSMC Tokyo. Should the storm intensify further and reach sustained wind speeds of 48 knots it will be classified as a severe tropical storm. Once the system's maximum sustained winds reach wind speeds of 64 knots, the JMA will designate the tropical cyclone as a typhoon—the highest category on its scale. From 2009 the Hong Kong Observatory started to further divide typhoons into three different classifications: typhoon, severe typhoon and super typhoon.
A typhoon has wind speed of 64-79 knots, a severe typhoon has winds of at least 80 knots, a super typhoon has winds of at least 100 knots. The United States' Joint Typhoon Warning Center unofficially classifies typhoons with wind speeds of at least 130 knots —the equivalent of a strong Category 4 storm in the Saffir-Simpson scale—as super typhoons. However, the maximum sustained wind speed measurements that the JTWC uses are based on a 1-minute averaging period, akin to the U. S.' National Hurricane Center and Central Pacific Hurricane Center. As a result, the JTWC's wind reports are higher than JMA's measurements, as the latter is based on a 10-minute averaging interval. There are six main requirements for tropical cyclogenesis: sufficiently warm sea surface temperatures, atmospheric instability, high humidity in the lower to middle levels of the troposphere, enough Coriol
Pacific Proving Grounds
The Pacific Proving Grounds was the name given by the United States government to a number of sites in the Marshall Islands and a few other sites in the Pacific Ocean at which it conducted nuclear testing between 1946 and 1962. The U. S. tested a nuclear weapon on Bikini Atoll on June 30, 1946. This was followed by Baker on July 24, 1946. On July 18, 1947, the United States secured an agreement with the United Nations to govern the islands of Micronesia as the Trust Territory of the Pacific Islands, a strategic trusteeship territory; this is the only such trusteeship granted by the United Nations. The Trust Territory comprised about 2,000 islands spread over 3,000,000 square miles of the North Pacific Ocean. Five days the United States Atomic Energy Commission established the Pacific Proving Grounds; the United States conducted 105 atmospheric and underwater nuclear tests in the Pacific, many of which were of high yield. While the Marshall Islands testing composed 14% of all U. S. tests, it composed nearly 80% of the total yields of those detonated by the U.
S. with an estimated total yield of around 210 megatons, with the largest being the 15 Mt Castle Bravo shot of 1954 which spread considerable nuclear fallout on many of the islands, including several which were inhabited, some that had not been evacuated. Many of the islands which were part of the Pacific Proving Grounds are still contaminated from the nuclear fallout, many of those who were living on the islands at the time of testing have suffered from an increased incidence of various health problems. Through the Radiation Exposure Compensation Act of 1990, at least $759 million has been paid to Marshall Islanders as compensation for their exposure to U. S. nuclear testing. Following the Castle Bravo accident, the U. S. paid $15.3 million to Japan. Scientists have calculated that the residents of the Marshall Islands during their lifetimes will be diagnosed with an added 1.6% cancers attributable to fallout-related radiation exposures. The cancers are the consequence of exposure to ionizing radiation from weapons test fallout deposited during the testing period and from residual radioactive sources during the subsequent 12 years.
On July 18, 1947, the United States convinced the United Nations to designate the islands of Micronesia as the Strategic Trust Territory. This was the only trust granted by the U. N; the directive stated that the United States should "promote the economic advancement and self-sufficiency of the inhabitants, to this end shall... protect the inhabitants against the loss of their lands and resources..."The United States Navy controlled the Trust from a headquarters in Guam until 1951, when the United States Department of the Interior took over control, administering the territory from a base in Saipan. Despite the promise to "protect the inhabitants", from July 1946 through July 1947, the residents of Bikini Atoll, relocated to Rongerik Atoll were starving for lack of food. A team of U. S. investigators concluded in late 1947. Press from around the world harshly criticized the U. S. Navy for ignoring the people. Harold Ickes, a syndicated columnist, wrote "The natives are and starving to death." The islanders were moved again to Kili Island, not surrounded by a reef.
The island does not support the inhabitants' traditional way of life. Because of the large amount of atmospheric testing, the Castle Bravo accident of 1954, many of the islands which were part of the Pacific Proving Grounds are still contaminated by nuclear fallout. Many of the island inhabitants at the time of testing suffered from increased incidence of various types of cancers and birth defects. Scientists calculated in 2010 that during the lifetimes of members of the Marshall Islands population exposed to ionizing radiation from weapons test fallout deposited during the testing period and from residual radioactive sources during the subsequent 12 years 1.6% of all cancers might be attributable to fallout-related radiation exposures. By sub-population, the projected proportion of cancers attributable to radiation from fallout from all nuclear tests conducted in the Marshall Islands is 55% among 82 persons exposed in 1954 on Rongelap Atoll and Ailinginae Atoll, 10% for 157 persons exposed on Utirik Atoll, 2.2% and 0.8% for the much larger populations exposed in mid-latitude locations including Kwajalein and in southern locations including Majuro.
Since 1956, the U. S. has paid at least $759 million to Marshall Islanders as compensation for their exposure to U. S. nuclear testing. Following the Castle Bravo accident on March 1, 1954, the U. S. paid $15.3 million to Japan. In June 1983, the U. S. and the Marshall islanders signed the Compact of Free Association, which gave the Marshall Islands independence. The Compact became effective in 1986 and was subsequently modified by the Amended Compact that became effective in 2004, it established the Nuclear Claims Tribunal, given the task of adjudicating compensation for victims and families affected by the nuclear testing program. Section 177 of the compact provided for reparations to the Bikini islanders and other northern atolls for damages, it included $150 million to be paid over a 15-year period ending in 2001. During that time, payments averaging about $18 million per year were made to the peoples of Bikini, Enewetak and Utrik for medical and radiological monitoring, in response to claims.
The payments began in 1987 with $2.4 mil
Nauru the Republic of Nauru and known as Pleasant Island, is an island country in Micronesia, a subregion of Oceania, in the Central Pacific. Its nearest neighbour is Banaba Island in 300 kilometres to the east, it further lies northwest of Tuvalu, north of the Solomon Islands, east-northeast of Papua New Guinea, southeast of the Federated States of Micronesia and south of the Marshall Islands. With only a 21-square-kilometre area, Nauru is the third-smallest state on the list of countries and dependencies by area behind Vatican City and Monaco, making it the smallest state in the South Pacific Ocean, the smallest island state, the smallest republic, its population is 11,347, making it the third smallest on the list of countries and dependencies by population, after the Vatican and Tuvalu. Settled by people from Micronesia and Polynesia c. 1000 BC, Nauru was annexed and claimed as a colony by the German Empire in the late 19th century. After World War I, Nauru became a League of Nations mandate administered by Australia, New Zealand and the United Kingdom.
During World War II, Nauru was occupied by Japanese troops, who were bypassed by the Allied advance across the Pacific. After the war ended, the country entered into United Nations trusteeship. Nauru gained its independence in 1968, became a member of the Pacific Community in 1969. Nauru is a phosphate-rock island with rich deposits near the surface, which allowed easy strip mining operations, it has some remaining phosphate resources which, as of 2011, are not economically viable for extraction. When the phosphate reserves were exhausted, the island's environment had been harmed by mining, the trust, established to manage the island's wealth diminished in value. To earn income, Nauru became a tax haven and illegal money laundering centre. From 2001 to 2008, again from 2012, it accepted aid from the Australian Government in exchange for hosting the Nauru Regional Processing Centre, an offshore Australian immigration detention facility; as a result of heavy dependence on Australia, many sources have identified Nauru as a client state of Australia.
Nauru was first inhabited by Polynesians at least 3,000 years ago. There were traditionally 12 clans or tribes on Nauru, which are represented in the twelve-pointed star on the country's flag. Traditionally, Nauruans traced their descent matrilineally. Inhabitants practised aquaculture: they caught juvenile ibija fish, acclimatised them to fresh water, raised them in the Buada Lagoon, providing a reliable source of food; the other locally grown components of their diet pandanus fruit. The name "Nauru" may derive from the Nauruan word Anáoero, which means'I go to the beach'; the British sea captain John Fearn, a whale hunter, became the first Westerner to visit Nauru, in 1798, calling it "Pleasant Island". From around 1830, Nauruans had contact with Europeans from whaling ships and traders who replenished their supplies fresh water, at Nauru. Around this time, deserters from European ships began to live on the island; the islanders firearms. The firearms were used during the 10-year Nauruan Tribal War that began in 1878.
After an agreement with Great Britain, Nauru was annexed by Germany in 1888 and incorporated into Germany's Marshall Islands Protectorate for administrative purposes. The arrival of the Germans ended the civil war, kings were established as rulers of the island; the most known of these was King Auweyida. Christian missionaries from the Gilbert Islands arrived in 1888; the German settlers called the island "Nawodo" or "Onawero". The Germans ruled Nauru for three decades. Robert Rasch, a German trader who married a Nauruan woman, was the first administrator, appointed in 1890. Phosphate was discovered on Nauru in 1900 by the prospector Albert Fuller Ellis; the Pacific Phosphate Company began to exploit the reserves in 1906 by agreement with Germany, exporting its first shipment in 1907. In 1914, following the outbreak of World War I, Nauru was captured by Australian troops. In 1919 it was agreed by the Allied and Associated Powers that His Britannic Majesty should be the administering authority under a League of Nations mandate.
The Nauru Island Agreement forged in 1919 between the governments of the United Kingdom and New Zealand provided for the administration of the island and for extraction of the phosphate deposits by an intergovernmental British Phosphate Commission. The terms of the League of Nations mandate were drawn up in 1920; the island experienced an influenza epidemic in 1920, with a mortality rate of 18 per cent among native Nauruans. In 1923, the League of Nations gave Australia a trustee mandate over Nauru, with the United Kingdom and New Zealand as co-trustees. On 6 and 7 December 1940, the German auxiliary cruisers Komet and Orion sank five supply ships in the vicinity of Nauru. Komet shelled Nauru's phosphate mining areas, oil storage depots, the shiploading cantilever. Japanese troops occupied Nauru on 25 August 1942; the Japanese built an airfield, bombed for the first time on 25 March 1943, preventing food supplies from being flown to Nauru. The Japanese deported 1,200 Nauruans to work as labourers in the Chuuk islands, occupied by Japan.
Nauru, bypassed and left to "wither on the vine" by US forces, was liberated on 13 September 1945, when commander Hisayaki Soeda surrendered the island to the Australian Army and the Royal Australian Navy. The surrender was accepted by Brigadier J. R. Stevenson, who represented Lieutenant General Vernon Sturdee, the commander of the First Australian Army, aboard the
Wake Island is a coral atoll in the western Pacific Ocean in the northeastern area of the Micronesia subregion, 1,501 miles east of Guam, 2,298 miles west of Honolulu, 1,991 miles southeast of Tokyo, 898 miles north of Majuro. The island is an unorganized, unincorporated territory of the United States, claimed by the Republic of the Marshall Islands. Wake Island is one of the most isolated islands in the world and the nearest inhabited island is Utirik Atoll in the Marshall Islands, 592 miles to the southeast. Wake Island, one of 14 U. S. insular areas, is administered by the United States Air Force under an agreement with the U. S. Department of the Interior; the center of activity on the atoll is at Wake Island Airfield, used as a mid-Pacific refueling stop for military aircraft and an emergency landing area. The 9,800-foot runway is the longest strategic runway in the Pacific islands. South of the runway is the Wake Island Launch Center, a missile launch site of the Ronald Reagan Ballistic Missile Defense Test Site operated by the United States Army Space and Missile Defense Command and the Missile Defense Agency.
The Base Operations Support contractor at Wake is Inc.. About 94 people live on the island, access to it is restricted. Population fluctuates depending on operations being conducted by Missile Defense Agency activities. On December 11, 1941, Wake Island was the site of the Empire of Japan's first unsuccessful attack on American forces in the Battle of Wake Island when U. S. Marines, with some US Navy personnel and civilians on the island repelled an attempted Japanese invasion, sinking two enemy destroyers and a transport; the island fell to overwhelming Japanese forces 12 days in a second attack, this one with extensive support from Japanese carrier-based aircraft returning from the attack on Pearl Harbor's naval and air bases in Hawaii further east, sixteen days previously. Wake Island remained occupied by Japanese forces until the end of the war in September 1945; the submerged and emergent lands at the atoll are a unit of the Pacific Remote Islands Marine National Monument. Wake island, together with eight other insular areas, comprises the United States Minor Outlying Islands, a statistical designation defined by the International Organization for Standardization's ISO 3166-1 code.
They are collectively represented by the ISO 3166-1 alpha-2 code UM. Wake Island derives its name from British sea captain Samuel Wake, who rediscovered the atoll in 1796 while in command of the Prince William Henry; the name is sometimes attributed to Capt. William Wake, reported to have discovered the atoll from the Prince William Henry in 1792. Wake is located two-thirds of the way from Honolulu to Guam. Honolulu is 2,300 statute miles to 1,510 statute miles to the west; the closest land is the uninhabited Bokak Atoll 348 mi in the Marshall Islands, to the southeast. The atoll is to the west of the International Date Line and in the Wake Island Time Zone, the easternmost time zone in the United States, one day ahead of the 50 states. Although Wake is called an island in the singular form, it is an atoll composed of three islets and a reef surrounding a central lagoon: Wake Island lies in the tropical zone, but is subject to periodic temperate storms during the winter. Sea surface temperatures are warm all year long, reaching above 80 °F in autumn.
Typhoons pass over the island. On October 19, 1940, an unnamed typhoon hit Wake Island with 120 knots winds; this was the first recorded typhoon to hit the island since observations began in 1935. Super Typhoon Olive barreled through Wake on September 1952 with wind speeds reaching 150 knots. Olive caused major flooding, destroyed 85% of its structures and caused $1.6 million in damages. On September 16, 1967, at 10:40 pm local time, the eye of Super Typhoon Sarah passed over the island. Sustained winds in the eyewall were 130 knots, from the north before the eye and from the south afterward. All non-reinforced structures were demolished. There were no serious injuries, the majority of the civilian population was evacuated after the storm. On August 28, 2006, the United States Air Force evacuated all 188 residents and suspended all operations as category 5 Super Typhoon Ioke headed toward Wake. By August 31 the southwestern eyewall of the storm passed over the island, with winds well over 185 miles per hour, driving a 20 ft storm surge and waves directly into the lagoon inflicting major damage.
A U. S. Air Force assessment and repair team returned to the island in September 2006 and restored limited function to the airfield and facilities leading to a full return to normal operations. Wake Island was first encountered by Europeans on October 2, 1568, by Spanish explorer and navigator Álvaro de Mendaña de Neyra. In 1567 Mendaña and his crew had set off on two ships, Los Reyes and Todos los Santos, from Callao, Peru, on an expedition to search for a gold-rich land in the South Pacific as mentioned in Inca tradition. After visiting Tuvalu and the Solomon Islands, the expedition headed north and came upon Wake Island, "a low barren island, judged to be eight leagues in circumference". Since the date – October 2, 1568 – was the eve of the feast of Saint Francis of Assisi, the captain named the island San Francisco; the ships were in need of water and the crew was suffering from scurvy, but after circling the island it was determined that Wake was waterless and h
South Pacific Mandate
The South Pacific Mandate was a League of Nations mandate given to the Empire of Japan by the League of Nations following World War I. The South Pacific Mandate consisted of islands in the north Pacific Ocean, part of German New Guinea within the German colonial empire until they were occupied by Japan during World War I. Japan governed the islands under the mandate as part of the Japanese colonial empire until World War II, when the United States captured the islands; the islands became the United Nations-established Trust Territory of the Pacific Islands governed by the United States. The islands are now part of Palau, Northern Mariana Islands, Federated States of Micronesia, Marshall Islands. In Japan, the territory is known as "Japanese mandate for the South Seas Islands" and was governed by the Nan'yō Government. Japan has few natural resources, the shortage of raw materials during industrialisation in the Meiji Restoration period meant that the development of the Japanese colonial empire was considered a political and economic necessity.
By the outbreak of WWI the empire included Taiwan, the Ryukyu Islands the southern half of Sakhalin island, the Kuril Islands, Port Arthur. The policy of Nanshin-ron, popular with the Imperial Japanese Navy, held that Southeast Asia and the Pacific Islands were the area of greatest potential value to the Japanese Empire for economic and territorial expansion; the Anglo-Japanese Alliance of 1902 had been signed to serve Britain's and Japan's common interest of opposing Russian expansion. Amongst other provisions the treaty called on each party to support the other in a war against more than one power, although it did not require a signatory state to go to war to aid the other. Within hours of Britain's declaration of war on Germany in 1914, Japan invoked the treaty and offered to declare war on the German Empire if it could take German territories in China and the South Pacific; the British government asked Japan for assistance in destroying the raiders from the Imperial German Navy in and around Chinese waters, Japan sent Germany an ultimatum demanding that it vacate China and the Marshall and Caroline islands.
The ultimatum went unanswered and Japan formally declared war on Germany on 23 August 1914. Japan participated in a joint operation with British forces in autumn 1914 in the Siege of Tsingtao to capture the Kiautschou Bay concession in China's Shandong Province; the Japanese Navy was tasked with pursuing and destroying the German East Asiatic Squadron and protection of the shipping lanes for Allied commerce in the Pacific and Indian Oceans. During the course of this operation, the Japanese Navy seized the German possessions in the Marianas, Marshall Islands and Palau groups by October 1914. After the end of World War I, the protectorate of German New Guinea was divided amongst the war's victors by the Treaty of Versailles; the southern part of the protectorate was mandated to come under Australian administration as the Territory of New Guinea, consisting of Kaiser-Wilhelmsland and the German-controlled islands south of the equator. Meanwhile, Japanese occupation of the northern part of the protectorate, consisting of the Micronesian islands north of the equator, was formally recognised by the treaty.
Japan was given a League of Nations Class C mandate to govern them, the terms of which specified that the islands should be demilitarised and Japan should not extend its influence further into the Pacific. The Mandate was subject to yearly scrutiny by the Permanent Mandates Commission of the League of Nations in Geneva, though by the late 1920s Tokyo was rejecting requests for official visitation or international inspection. Following the initial Japanese occupation of the islands, a policy of secrecy was adopted. Japan made it plain that it did not welcome the entry of foreign ships into Micronesian waters those of its wartime allies. During the first five years that Japan occupied the islands, it consolidated its presence and the islands became a virtual Japanese colony; the Imperial Japanese Navy divided the territory into five naval districts in Palau, Truk and Jaluit Atoll, all reporting to a rear admiral at the naval headquarters at Truk. A proposal at the Versailles Conference to allow trade and migration between those islands to be administered by Japan and those to be administered by Australia and New Zealand was rejected.
Japan was able to continue administering the islands as if they were colonial possessions, keeping their waters off limits to foreigners. When the islands became a League of Nations Mandate, Japan administered them as Japanese territory and as part of the Japanese Empire; this situation continued after Japan withdrew from the League of Nations in 1935 and lost its legal claim to administer the islands. Militarily and economically, Saipan, in the Marianas archipelago, was the most important island in the South Pacific Mandate and became the center of subsequent Japanese settlement; the towns of Garapan and Colony were developed to resemble small towns in Japan, with cinemas, beauty parlours and geisha houses. Another important island was Truk in the Carolines archipelago, fortified into a major navy base by the Imperial Japanese Navy. Between 1914 and 1920 the islands began the slow transition from naval to civilian administration. By 1920 all authority had been transferred from the Naval Defense Force to the Civil Affairs Bureau, directly responsible to the Navy Ministry.
Based in Truk, the Civil Affairs Bureau was moved to Koror in the
Enewetak Atoll is a large coral atoll of 40 islands in the Pacific Ocean and with its 664 people forms a legislative district of the Ralik Chain of the Marshall Islands. With a land area total less than 5.85 square kilometres, it is no higher than 5 meters and surrounds a deep central lagoon, 80 kilometres in circumference. It is 305 kilometres west from Bikini Atoll, it was held by the Japanese from 1914 until its capture by the United States in February of 1944, during World War II. Nuclear testing by the US totaling more than 30 megatons of TNT took place during the cold war; the Runit Dome is deteriorating and could be breached by a typhoon, though the sediments in the lagoon are more radioactive than those which are contained. The U. S. government referred to the atoll as "Eniwetok" until 1974, when it changed its official spelling to "Enewetak". Enewetak Atoll formed atop a seamount; the seamount was formed in the late Cretaceous. This seamount is now about 1,400 metres below sea level, it is made of basalt, its depth is due to a general subsidence of the entire region and not because of erosion.
Enewetak has a mean elevation above sea level of 3 metres. Humans have inhabited the atoll since about 1,000 B. C; the first European visitor to Enewetak, Spanish explorer Alvaro de Saavedra, arrived on 10 October 1529. He called the island "Los Jardines". In 1794 sailors aboard the British merchant sloop Walpole called the islands "Brown's Range", it was visited by about a dozen ships before the establishment of the German colony of the Marshall Islands in 1885. With the rest of the Marshalls, Enewetak was captured by the Imperial Japanese Navy in 1914 during World War I and mandated to the Empire of Japan by the League of Nations in 1920; the Japanese administered the island under the South Pacific Mandate, but left affairs in hands of traditional local leaders until the start of World War II. The atoll, together with other part of Marshall Islands located to the west of 164°E, was placed under the governance of Pohnpei district during the Japanese administration period, is different from rest of Marshall Islands.
In November 1942, the Japanese built an airfield on Engebi Island. As they used it only for refueling planes between Truk and islands to the east, no aviation personnel were stationed there and the island had only token defenses; when the Gilberts fell to the United States, the Imperial Japanese Army assigned defense of the atoll to the 1st Amphibious Brigade, formed from the 3rd Independent Garrison, stationed in Manchukuo. The 1st Amphibious Brigade arrived on January 4, 1944; some 2,586 of its 3,940 men were left to defend Eniwetok Atoll, supplemented by aviation personnel, civilian employees, laborers. However, they were unable to finish the fortifications. During the ensuing Battle of Eniwetok, the Americans captured Enewetak in a five-day amphibious operation. Fighting took place on Engebi Islet, site of the most important Japanese installation, although some combat occurred on the main islet of Enewetak itself and on Parry Island, where there was a Japanese seaplane base. Following its capture, the anchorage at Enewetak became a major forward base for the U.
S. Navy; the daily average of ships present during the first half of July 1944 was 488. In 1950, John C. Woods, who executed the Nazi war criminals convicted at the Nuremberg Trials, was accidentally electrocuted here. After the end of World War II, Enewetak came under the control of the United States as part of the Trust Territory of the Pacific Islands until the independence of the Marshall Islands in 1986. During its tenure, the United States evacuated the local residents many times involuntarily; the atoll was used for nuclear testing as part of the Pacific Proving Grounds. Before testing commenced, the U. S. exhumed the bodies of United States servicemen killed in the Battle of Enewetak and returned them to the United States to be re-buried by their families. Forty-three nuclear tests were fired at Enewetak from 1948 to 1958; the first hydrogen bomb test, code-named Ivy Mike, occurred in late 1952 as part of Operation Ivy. This test included B-17 Flying Fortress drones to fly through the radioactive cloud to test onboard samples.
B-17 mother ships controlled the drones while flying within visual distance of them. In all 16 to 20 B-17s took part in this operation, of which half were controlling aircraft and half were drones. To examine the explosion clouds of the nuclear bombs in 1957/58 several rockets were launched. One USAF airman was lost at sea during the tests. A radiological survey of Enewetak was conducted from 1972 to 1973. In 1977, the United States military began decontamination of other islands. During the three-year, US$100 million cleanup process, the military mixed more than 80,000 cubic metres of contaminated soil and debris from the islands with Portland cement and buried it in an atomic blast crater on the northern end of the atoll's Runit Island; the material was placed in the 9.1-metre deep, 110-metre wide crater created by the May 5, 1958, "Cactus" nuclear weapons test
Sea level rise
Since at least the start of the 20th century, the average global sea level has been rising. Between 1900 and 2016, the sea level rose by 16–21 cm. More precise data gathered from satellite radar measurements reveal an accelerating rise of 7.5 cm from 1993 to 2017, a trend of 30 cm per century. This acceleration is due to human-caused global warming, driving thermal expansion of seawater and the melting of land-based ice sheets and glaciers. Between 1993 and 2018, thermal expansion of the oceans contributed 42% to sea level rise. Climate scientists expect the rate to further accelerate during the 21st century. Projecting future sea level is challenging, due to the complexity of many aspects of the climate system; as climate research into past and present sea levels leads to improved computer models, projections have increased. For example, in 2007 the Intergovernmental Panel on Climate Change projected a high end estimate of 60 cm through 2099, but their 2014 report raised the high-end estimate to about 90 cm.
A number of studies have concluded that a global sea level rise of 200 to 270 cm this century is "physically plausible". A conservative estimate of the long-term projections is that each Celsius degree of temperature rise triggers a sea level rise of 2.3 metres over a period of two millennia: an example of climate inertia. The sea level will not rise uniformly everywhere on Earth, it will drop in some locations. Local factors include tectonic effects and subsidence of the land, tides and storms. Sea level rises can influence human populations in coastal and island regions. Widespread coastal flooding is expected with several degrees of warming sustained for millennia. Further effects are higher storm-surges and more dangerous tsunamis, displacement of populations and degradation of agricultural land and damage in cities. Natural environments like marine ecosystems are affected, with fish and plants losing parts of their habitat. Societies can respond to sea level rise in three different ways: to retreat, to accommodate and to protect.
Sometimes these adaptation strategies go hand in hand, but at other times choices have to be made among different strategies. Ecosystems that adapt to rising sea levels by moving inland might not always be able to do so, due to natural or man-made barriers. Understanding past sea level is important for the analysis of current and future changes. In the recent geological past, changes in land ice and thermal expansion from increased temperatures are the dominant reasons of sea level rise; the last time the Earth was 2 °C warmer than pre-industrial temperatures, sea levels were at least 5 metres higher than now: this was when warming because of changes in the amount of sunlight due to slow changes in the Earth's orbit caused the last interglacial. The warming was sustained over a period of thousands of years and the magnitude of the rise in sea level implies a large contribution from the Antarctic and Greenland ice sheets. Since the last glacial maximum about 20,000 years ago, the sea level has risen by more than 125 metres, with rates varying from less than a mm/year to 40+ mm/year, as a result of melting ice sheets over Canada and Eurasia.
Rapid disintegration of ice sheets led to so called'meltwater pulses', periods during which sea level rose rapidly. The rate of rise started to slow down about 8,200 years before present. Sea level changes can be driven either by variations in the amount of water in the oceans, the volume of the ocean or by changes of the land compared to the sea surface; the different techniques used to measure changes in sea level do not measure the same. Tide gauges can only measure relative sea level, whilst satellites can measure absolute sea level changes. To get precise measurements for sea level, researchers studying the ice and the oceans on our planet factor in ongoing deformations of the solid Earth, in particular due to landmasses still rising from past ice masses retreating, the Earth's gravity and rotation. Since the 1992 launch of TOPEX/Poseidon, altimetric satellites have been recording the change in sea level; those satellites can measure the hills and valleys in the sea caused by currents and detect trends in their height.
To measure the distance to the sea surface, the satellite sends a microwave pulse to the ocean's surface and records the time it takes to return. A microwave radiometer corrects any delay. Combining this data with the precise location of the spacecraft makes it possible to determine sea-surface height to within a few centimeters. Current rates of sea level rise from satellite altimetry have been estimated to be 3.0 ± 0.4 millimetres per year for the period 1993–2017. Earlier satellite measurements were at odds with tide gauge measurements. A small calibration error for the Topex/Poseidon satellite discovered in 2015 was identified as the cause of this mismatch, it had caused a slight overestimation of the 1992–2005 sea levels, which masked the ongoing sea level rise acceleration. Satellites are useful for measuring regional variations in sea level, such as the substantial rise between 1993 and 2012 in the western tropical Pacific; this sharp rise has been linked to increasing trade winds, which occur when the Pacific Decadal Oscillation and the El Niño–Southern Oscillation change from one state to t