Micronesia geographical location. Report: Micronesia and Polynesia

general characteristics

Definition 1

Micronesia is a combination of several groups of small islands in Oceania: the Gilbert Islands, the Marshall Islands, the Mariana Islands and some others - more than 1.5 thousand islands in total. Micronesia is distinguished by small land areas (2.6 thousand square kilometers) and significant maritime economic zones.

Micronesia owns the following dependent territories and states:

Nauru;
Kiribati (Gilbert Islands);
Marshall Islands (United States of America);
Federated States Micronesia;
Guam (United States of America);
Palau (United States of America);
Northern Mariana Islands (United States of America).

Geographically, Micronesia is divided into: the Caroline Islands, the Marshall Islands, the Kiribati Islands, the Mariana Islands and the island of Nauru. The Marianas and the Western Carolinas are islands of volcanic origin.

The largest atolls: Rongelap (Rimsky-Korsakov); Bikini (Eschsholtz); Maloelap (Arakcheeva); Eniwetok (Brown); Majuro; Kusaie, Tarava, Uliti, Senyavina, Truk.

Marshall Islands

The Marshall Islands are a group of islands and atolls located north of the equator in the Pacific Ocean. The islands and atolls form two chains: Ralik and Ratak, stretching from the northwest to the southeast for 1200 km. The largest islands are Majuro and Kwajalein. Kwajalein is an atoll with the largest lagoon in the world.

The nearest archipelagos are the Gilbert Islands (Republic of Kiribati) and the Caroline Islands (Federated States of Micronesia). The Marshall Islands occupy 181.3 square kilometers. km, lagoons - 11,673 sq. km.

The relief of all the islands is low, highest point(10 m) is located on the Likiep Atoll. The atolls are made up of a large number of motu - small islands formed as a result of the rise of a coral reef.

extreme atolls Marshall Islands are:

Bokak Island (Taongi) - north;
Ebon Atoll - south;
Ujelang Atoll - west; Knox atoll - east.

The Marshall Islands is a huge exclusive economic zone, which is characterized by limited natural resources, shortage of qualified specialists, remoteness from the main world sales markets. Economic difficulties are manifested in the state budget deficit, the low level of domestic savings, and the lack of balance of payments. The country is highly dependent on finance provided by the Asian Development Bank.

The most stable components in the economy at present are the public sector, economic and financial revenues from the Reagan Test Site (United States) located on Kwajalein Atoll.

Main sectors of the economy: agriculture and services. Food crops are grown mainly for personal consumption (breadfruit, coconut palm, bananas, pandanus, taro, cucumbers, watermelons, pineapples, peppers, eggplants, tomatoes, cabbage, etc.). The most important agricultural product is copra.

The priority sector of the economy is fishing. The population catches coastal fish, crabs. The main export is tuna. Pearl farms operate on the atolls of Majuro and Namorik, and a station for growing tridacnids operates on Likiep.

Tourism is developing dynamically. The state is a popular offshore zone.

Caroline and Mariana Islands

The Caroline Islands include about 1000 grouped and individual islands and atolls. The total area of the territory is about 1160 sq. km. The largest islands and groups: the western group - Palau (Babeltuap Island) and Yap; the eastern group is the islands of Senyavina, Truk, Kusaiye.

All major islands of volcanic origin are surrounded by coral reefs. The islands of the eastern group formed on the ocean floor, while the islands of the western group belong to the totality of island arcs and experience a constant slow rise.

Mariana Islands - an island arc located in a seismically active zone in the western regions Pacific Ocean. The islands are located at an equal distance (2500 km) from the Philippines and Papua New Guinea.

The Mariana Islands include such large islands as: Agihan, Alamagan, Agrihan, Anatahan, Guam, Asuncion, Guguan, Maug, Rota, Pagan, Saipan, Tinian, Sarigan, Farallion de Medinilla, Farallion de Pajaros.

There are many underwater volcanoes around the islands. More than 10 volcanoes form the islands themselves.

Islands of Kiribati. Nauru

All the islands of Caribati are atolls (32 low-lying atolls and one elevated - Banaba). The total land area is 812.34 sq. km.

All islands of Kiribati are divided into groups:

Gilbert Archipelago.
Banaba Island.
Phoenix Archipelago.
Archipelago Line.

Kiribati is an agricultural country. Its economy is dominated by the public sector. Characterized by slow economic growth and a low level of services. The difficulties of economic development are associated with remoteness from world sales markets, vulnerability to natural disasters, geographical dispersion, a limited domestic market, and small labor resources.

The only way for economic development lies in attracting monetary assistance and financial transfers from other states, attracting migrants.

The main source of income for the islands of Kiribati are fish products and copra. The main employer is the state.

There are natural obstacles for the development of agriculture - small areas of atolls. High level of land cultivation technology. The development of agriculture has had an adverse effect on the vegetation cover of the islands and led to deforestation. The most important agricultural crop is the giant marsh taro. Pandanus, papaya, breadfruit are also cultivated. V Lately production of copra, the main export commodity of the country, increased.

Nauru is a coral island located in southern Micronesia in the western Pacific Ocean near the equator. The total area of the territory is 21.3 square meters. km. Nauru is one of the rare coral islands - a raised atoll. The island has several small lakes Anabar and freshwater lake Buada (remnant of an ancient lagoon).

Micronesia and Polynesia

micronesia

Micronesia (Greek: Small Island) includes the Volkano, Bonin, Mariana, Caroline, Marshall, Gilbert, Ellis and Nauru and Ocean archipelagos. As the name suggests, all these islands are small; the largest of them, Guam (the Mariana Islands), has an area of 583 km2. The western archipelagos of Micronesia from Volkano to the western Caroline Islands are located in the belt of geosynclinal structures of the Pacific Ocean floor and are the tops of volcanoes rising from a folded underwater ridge. The relief of the ocean floor in western Micronesia is extremely dissected. It is here, along the eastern edge of the Mariana Island Arc, that one of the world's deepest depressions, the Mariana Trench, lies (the greatest depth is 11,034 m). Tectonic activity earth's crust expressed very clearly. There are frequent and strong earthquakes and volcanic eruptions. The islands have a mountainous relief (height from 400 to 1000 m), framed by abrasion terraces and coral reefs. Some of them, composed only of limestone, have a very strongly karst and rugged surface. The islands of eastern Micronesia are coral. They crown the volcanic peaks of the platform bottom of the Pacific Ocean and rarely rise above the water by more than 1.5-2.5 m. Very many of them have the shape of typical atolls. The islands lie in latitudes from equatorial to subtropical, but under the influence of the warm Kuro-Sivo current, the climate of the northern islands is as hot and humid as that of the southern ones. The largest number precipitation (from 1500 mm to 2000 mm) falls on the eastern slopes of the mountainous islands windward with respect to the northeast trade winds. In its natural state, the slopes were covered with dense moist evergreen tropical forests of areca palms (Areca catechu), pandanus (Pandanus spp.), breadfruit (Artocarpus spp.), Polynesian iron tree (Casuarina equisetifolla). These forests have not only drastically shrunk in area, but have also been altered by the felling of valuable species. The leeward slopes of the islands are occupied by cereal savannahs, most likely secondary. The atolls of eastern Micronesia are dominated by the coconut palm, and the inland lagoons are lined with mangroves.

Polynesia

Polynesia (Greek: Multi-island) unites islands lying generally east of the 180 meridian, between 30 ° N. sh. and 30°S sh. : Hawaiian, atoll and reef islands Line (Sporades), coral archipelagos of Phoenix and Tokelau, volcanic archipelago of Samoa with active volcanoes, a two-row chain of volcanic (western row) and coral (eastern row) islands of Tonga, Cook Islands, Tubuai, Society with volcanic island Tahiti, 76 Tuamotu atolls, or Russians, Marquesas and, finally, the secluded Easter Island, with which the myth of the Pacific Atlantis is associated. The islands are the peaks of basalt volcanoes, mostly decapitated by weathering and abrasion, completely or partially covered by reef limestones. coral islands product of the ocean, stony corals and calcareous algae. The atolls are in the form of a ring of low reefs from 2 to 150 km in diameter. Rings are solid or open and surround inland shallow lagoons. Strong surf destroys the outer edge of the coral shores; waves throw debris at the edges of the atolls, where an outer ridge grows, cemented by salts sea water. In strong winds, detrital material is transported deep into the atolls and fills the lagoons. The organic world is represented by reef-loving plants and animals not only on land, but also on the sea, and in some cases it is difficult to determine where the ocean biotope ends and the land biotope begins. Along the outer edge of the atoll, on reefs and beaches, at low tide, there are many marine organisms that tolerate a short stay in the air, seaweed, unicellular foraminifera animals with a limestone skeleton, sponges, sea urchins and starfish remaining in deep pools, some holothurians burrowing into the sand, crabs and shrimps. Behind the outer crest of the atoll, on thin carbonate soils, terrestrial vegetation appears, which tolerates soil salinity and a high salt content in the air, thickets of evergreen xerophytic shrubs, forests of coconut palms, pandanus trees, banana thickets and groves of breadfruit trees. Apparently, this vegetation is largely of anthropogenic origin; in its natural state, the flora of the islands is limited to very few species of shrubs and trees. On the atolls, one can observe the operation of the great law of nature, according to which living beings, born in the ocean, subsequently moved to land. Palm thief crab lives in coconut groves and forests, living in sandy burrows. It climbs palm trees, pierces the dense shells of nuts with powerful ticks and feeds on their pulp. This crab has long adapted to a land-based lifestyle, but still goes to the sea for the breeding season.

Another, even more striking example is the mudskipper, a fish that lives in murky waters among the mangroves that surround the inner lagoons of the atolls. With the help of strong fins, she climbs tree trunks and spends up to 10-20 minutes in the air, hunting for insects. Mangrove forests are an indispensable frame for lagoons. In the muddy bottom of the bottom, along with mangroves, some seaweeds live, and limestone algae are entwined with mangrove roots. Almost all types of landscapes of Polynesia are represented on the largest archipelago of the Hawaiian Islands, stretching for 2500 km. They mark the highest peaks of the underwater Hawaiian Ridge, more than 6500 km long, and are concentrated in its southern third, the most elevated. The Hawaiian archipelago is made up of 24 islands. with total area 16,700 km2, of which 16,273 km2 is on the island of Hawaii (10,399 km2 and the islands of Maui, Oahu, Kauai, Molokan and Lanai. The island of Hawaii is formed by five merged volcanoes, of which Mauna Kea (4170 m] and Kilauea (1247 m) continue to be active other volcanoes, including highest peak in Polynesia Mauna Kea (4210 m), extinct. The volcanoes of the island have retained the gentle slopes characteristic of shield cones, Mauna Loa and Kilauea have huge flat-bottomed craters with lakes of gushing lava, which, during eruptions, overflows over the edges of the craters and rushes down the slopes at high speed, burning all living things in its path. On the other large islands, volcanic activity ceased at the beginning of the Quaternary, and the primary forms of volcanoes were transformed by erosion and denudation into a heavily rugged mountainous terrain. On small islands, volcanism waned at the end of the Neogene, and prolonged weathering and abrasion destroyed the volcanoes almost entirely. The central link of the archipelago is formed by small rocky peaks and reefs (Nihoa, Necker, Gardner, etc.), the northwestern one is coral atolls and reefs. Most of the islands are stretched in the tropical climate zone and are under the continuous influence of the northeast trade winds. Abundant orographic rains moisten the windward slopes of the mountainous islands (up to 4000 mm at an altitude of about 2000 m, and the island of Kauai receives more than 12500 mm of precipitation per year, almost as much as in Cherrapunji, India). On the leeward slopes, a lot of precipitation falls only at high altitudes, the rest of the regions are dry (no more than 700 mm of precipitation per year) and hot; tropical heat is aggravated by foehn winds flowing down the slopes. In winter, moist Kona winds blow on the islands, which drag equatorial air along the western periphery of the Hawaiian anticyclone into the cyclonic depressions of the polar front passing over the northwestern part of the Kona archipelago, often reaching storm strength and bringing sudden showers.

The northwestern islands of the archipelago lie in the subtropical climate zone, but, far from the cold California current, they have higher average seasonal temperatures; precipitation is cyclonic, with a maximum in winter (on Midway Island, 1070 mm falls annually). The flora of Hawaii is highly endemic (up to 93 species) and monotonous, as a result of which it stands out in a special Hawaiian subregion of the Paleotropics. It lacks gymnosperms, ficuses, epiphytic orchids. Palm trees are represented by only three species. Mountain-forest landscapes with vertical zonality are developed on the northern and northeastern slopes; dry forests, savannahs, and even arid shrubs predominate on the southern and southwestern slopes. In the lower forest belt (up to a height of 600-700 m), where moisture is not yet high enough, seasonally wet mixed (deciduous-evergreen) forests develop, in the middle zone (up to 1200 m) permanently wet evergreen forests. From 1200 m to the upper forest line (3000 m) they are replaced by tropical mountain hylaea. In the Hawaiian forests, now heavily cut down, there are many trees with valuable timber. Significance in the 19th century had sandalwood (Santalum album) with aromatic wood, now almost destroyed. On the summit volcanic plateaus, lying in the temperate mountain zone on fresh, unweathered lavas, ferns are the first settlers, followed by shrubs, composite and xerophytic grasses. Savannahs do not climb slopes higher than 300-600 m. Xerophytic herbs hilo (Heteropogon contortus) and pili (Cynadon dactylon) form a dense sod cover in them, preventing the appearance of woody vegetation, which is why trees (Pandanus spp., erythri-na monosperma) grow scattered rare groups. Vegetation on small islands is represented by rare xerophytic shrubs and tough grasses, many rocky islands are completely bare. Under the savannas, especially under the forests, soils of the lateritic series develop, highly saturated with titanium and iron oxides in accordance with the chemical composition of the lavas. The complete reduction of forests for plantations led to intense erosion, and the long-term use of soils without the addition of the necessary fertilizers led to their severe depletion. The avifauna (67 genera) is very richly represented on the islands. More than half of the birds are sedentary and nest on islands (mainly on small ones, which, with the exception of Midway Island, are declared a bird reservation). Many forest bird species have beautiful plumage. Among them stand out the endemic family of Hawaiian flower girls and the endemic genus of honeyeaters.

Some birds come to the islands for the winter from North America and northeast Asia. In addition to birds from the Hawaiian fauna proper, there is one species of bat, several species of lizards (geckos, skinks), and beetles. On the Hawaiian Islands consciously and accidentally, a lot of plants from all over the world were brought in, including weeds that got on them, which spread widely and displaced the local flora in many areas; many animals, as well as birds and insects, also came to the islands, some of which also bring great harm. Rabbits, cats, pigs and rats have bred incredibly.

Bibliography

For the preparation of this work, materials from the site http://rgo.ru were used.

micronesia

Micronesia (Greek: Small Island) includes the Volkano, Bonin, Mariana, Caroline, Marshall, Gilbert, Ellis and Nauru and Ocean archipelagos. As the name suggests, all these islands are small; the largest of them, Guam (the Mariana Islands), has an area of 583 km2. The western archipelagos of Micronesia from Volkano to the western Caroline Islands are located in the belt of geosynclinal structures of the Pacific Ocean floor and are the tops of volcanoes rising from a folded underwater ridge. The relief of the ocean floor in western Micronesia is extremely dissected. It is here, along the eastern edge of the Mariana Island Arc, that one of the world's deepest depressions, the Mariana Trench, lies (the greatest depth is 11,034 m). The tectonic activity of the earth's crust is very pronounced. There are frequent and strong earthquakes and volcanic eruptions. The islands have a mountainous relief (height from 400 to 1000 m), framed by abrasion terraces and coral reefs. Some of them, composed only of limestone, have a very strongly karst and rugged surface. The islands of eastern Micronesia are coral. They crown the volcanic peaks of the platform bottom of the Pacific Ocean and rarely rise above the water by more than 1.5-2.5 m. Very many of them have the shape of typical atolls. The islands lie in latitudes from equatorial to subtropical, but under the influence of the warm Kuro-Sivo current, the climate northern islands as hot and humid as the south. The greatest amount of precipitation (from 1500 mm to 2000 mm) falls on the eastern slopes of the mountainous islands windward with respect to the northeast trade winds. In its natural state, the slopes were covered with dense moist evergreen tropical forests of areca palms (Areca catechu), pandanus (Pandanus spp.), breadfruit (Artocarpus spp.), Polynesian iron tree (Casuarina equisetifolla). These forests have not only drastically shrunk in area, but have also been altered by the felling of valuable species. The leeward slopes of the islands are occupied by cereal savannahs, most likely secondary. The atolls of eastern Micronesia are dominated by the coconut palm, and the inland lagoons are lined with mangroves.

Polynesia

Polynesia (Greek: Multi-island) unites islands lying generally east of the 180 meridian, between 30 ° N. sh. and 30°S sh .: Hawaiian, atoll and reef islands Line (Sporades), coral archipelagos of Phoenix and Tokelau, volcanic archipelago of Samoa with active volcanoes, a two-row chain of volcanic (western row) and coral (eastern row) islands of Tonga, Cook Islands, Tubuai, Societies with the volcanic island of Tahiti, 76 Tuamotu atolls, or Russians, Marquesas and, finally, the secluded Easter Island, with which the myth of the Pacific Atlantis is associated. The islands are the peaks of basalt volcanoes, mostly decapitated by weathering and abrasion, completely or partially covered by reef limestones. Coral islands are a product of the ocean, stony corals and calcareous algae. The atolls are in the form of a ring of low reefs from 2 to 150 km in diameter. Rings are solid or open and surround inland shallow lagoons. Strong surf destroys the outer edge of the coral shores; waves throw debris at the edges of the atolls, where an outer ridge grows, cemented by salts of sea water. In strong winds, detrital material is transported deep into the atolls and fills the lagoons. The organic world is represented by reef-loving plants and animals not only on land, but also on the sea, and in some cases it is difficult to determine where the ocean biotope ends and the land biotope begins. Along the outer edge of the atoll, on reefs and beaches at low tide, there are many marine organisms that endure a short stay in the air, seaweed, unicellular animals foraminifera with a limestone skeleton, sponges, sea urchins and starfish remaining in deep puddles, some holothurians burrowing in sand, crabs and shrimps. Behind the outer crest of the atoll, on thin carbonate soils, terrestrial vegetation appears, which tolerates soil salinity and a high salt content in the air, thickets of evergreen xerophytic shrubs, forests of coconut palms, pandanus trees, banana thickets and groves of breadfruit trees. Apparently, this vegetation is largely of anthropogenic origin; in its natural state, the flora of the islands is limited to very few species of shrubs and trees. On the atolls, one can observe the operation of the great law of nature, according to which living beings, born in the ocean, subsequently moved to land. Palm thief crab lives in coconut groves and forests, living in sandy burrows. It climbs palm trees, pierces the dense shells of nuts with powerful ticks and feeds on their pulp. This crab has long adapted to a land-based lifestyle, but still goes to the sea for the breeding season.

Another, even more striking example is the mudskipper, a fish that lives in murky waters among the mangroves that surround the inner lagoons of the atolls. With the help of strong fins, she climbs tree trunks and spends up to 10-20 minutes in the air, hunting for insects. Mangrove forests are an indispensable frame for lagoons. In the muddy bottom of the bottom, along with mangroves, some seaweeds live, and limestone algae are entwined with mangrove roots. Almost all types of landscapes of Polynesia are represented on the largest archipelago of the Hawaiian Islands, stretching for 2500 km. They mark the highest peaks of the underwater Hawaiian Ridge, more than 6500 km long, and are concentrated in its southern third, the most elevated. The Hawaiian archipelago consists of 24 islands with a total area of 16,700 km2, of which 16,273 km2 falls on the island of Hawaii (10,399 km2 and the islands of Maui, Oahu, Kauai, Molokan and Lanai. Five merged volcanoes form the island of Hawaii, of which Mauna Kea (4170 m) and Kilauea (1247 m) are still active.Other volcanoes, including the highest peak in Polynesia, Mauna Kea (4210 m), are extinct. with lakes of gushing lava, which, during eruptions, overflows over the edges of craters and rushes down the slopes at high speed, burning all living things in its path. major islands volcanic activity ceased at the beginning of the Quaternary, and the primary forms of the volcanoes were transformed by erosion and denudation into a heavily rugged mountainous terrain. On small islands, volcanism waned at the end of the Neogene, and prolonged weathering and abrasion destroyed the volcanoes almost entirely. The central link of the archipelago is formed by small rocky peaks and reefs (Nihoa, Necker, Gardner, etc.), the northwestern one is coral atolls and reefs. Most of the islands are stretched in the tropical climate zone and are under the continuous influence of the northeast trade winds. Abundant orographic rains moisten the windward slopes of the mountainous islands (up to 4000 mm at an altitude of about 2000 m, and the island of Kauai receives more than 12500 mm of precipitation per year, almost as much as in Cherrapunji, India). On the leeward slopes, a lot of precipitation falls only at high altitudes, the rest of the regions are dry (no more than 700 mm of precipitation per year) and hot; tropical heat is aggravated by foehn winds flowing down the slopes. In winter, moist Kona winds blow on the islands, which drag equatorial air along the western periphery of the Hawaiian anticyclone into the cyclonic depressions of the polar front passing over the northwestern part of the Kona archipelago, often reaching storm strength and bringing sudden showers.

Some birds come to the islands for wintering from North America and northeast Asia. In addition to birds from the Hawaiian fauna proper, there is one species of bat, several species of lizards (geckos, skinks), and beetles. A lot of plants from all over the world were deliberately and accidentally brought to the Hawaiian Islands, including weeds that got on them, which greatly spread and displaced the local flora in many areas; many animals, as well as birds and insects, also came to the islands, some of which also bring great harm. Rabbits, cats, pigs and rats have bred incredibly.