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1、Unit Two,Geography,英美概况 主编：齐智英,Contents,英美概况 主编：齐智英,Unit Two,2.1. The Locations of the UK and the USA 2.1.1 The Location of the UK The United Kingdom of Great Britain and Northern Ireland is in Western Europe, to the northwest of mainland Europe. The United Kingdom has a total area of approximately
2、245,000 square kilometers (94,600 square miles). It comprises the island of Great Britain (most of England, Scotland and Wales) and the northeastern one-sixth of the island of Ireland (Northern Ireland), together with many smaller islands. The mainland areas lie between latitudes 49N and 59N (the Sh
3、etland Islands reach to nearly 61N), and longitudes 8W to 2E. The Royal Greenwich Observatory, near London, is the defining point of the Prime Meridian. The UK lies between the North Atlantic Ocean and the North Sea, and comes within 35 kilometers of the northwest coast of France, from which it is s
4、eparated by the English Channel. The Channel Tunnel now links the UK with France beneath the English Channel. Northern Ireland shares a 360 kilometers land boundary with the Republic of Ireland.,Unit Two,Unit Two,2.1.2 The Location of the USA The United States is situated almost entirely in the west
5、ern hemisphere: the contiguous United States stretches from the Pacific on the west to the Atlantic on the east, with the Gulf of Mexico to the southeast, and bordered by Canada on the north and Mexico on the south. Alaska is the largest state in area, separated from the contiguous US by Canada, it
6、touches the Pacific on the south and Arctic Ocean on the north. Hawaii occupies an archipelago in the central Pacific, southwest of North America. Including only land area, the United States is third in size behind Russia and China, just ahead of Canada. The United States also possesses several insu
7、lar territories scattered around the West Indies (e.g.: the Commonwealth of Puerto Rico) and the Pacific (e.g.: Guam).,Unit Two,Unit Two,2.2 Climate of the UK and the USA 2.2.1 The Climate of the UK The climate of the United Kingdom is classified as a mid-latitude oceanic climate with warm summers,
8、cool winters and plentiful precipitation throughout the year. The temperature varies with the seasons but seldom drops below 10 C (14 F) or rises above 35 C (95 F). The prevailing wind is from the southwest, bearing frequent spells of mild and wet weather from the Atlantic Ocean. Eastern parts are m
9、ost sheltered from this wind and are therefore the driest. Atlantic currents, warmed by the Gulf Stream1, bring mild winters, especially in the west, where winters are also wet, especially over high ground. Summers are warmest in the south east of England, being closest to the European mainland, and
10、 coolest in the north. Another factor that influences the countrys climate is its northerly latitude (which ranges from 50N to 60 N). Snowfall can occur in winter and early spring, though it rarely settles to any great depth away from high ground,Unit Two,Unit Two,The boundary of convergence between
11、 the warm tropical air and the cold polar air lies over the United Kingdom. In this area, the large temperature variation creates instability and this is a major factor that influences the notoriously changeable and often unsettled weather the country experiences, where many types of weather can be
12、experienced in a single day.,Unit Two,Unit Two,2.2.2 The Climate of the USA Because of the United States large size and wide range of geographic features, nearly every type of climate is represented. The climate is temperate in most areas, tropical in Hawaii and southern Florida, polar in Alaska, se
13、miarid in the Great Plains west of the 100th meridian, Mediterranean in coastal California and arid in the Great Basin. Its comparatively generous climate contributed (in part) to the countrys rise as a world power, with infrequent severe drought in the major agricultural regions, a general lack of
14、widespread flooding, and a mainly temperate climate that receives adequate precipitation. Extreme weather is not uncommonthe states bordering the Gulf of Mexico are prone to hurricanes, and most of the worlds tornadoes occur within the continental United States, primarily in the Midwest.,Unit Two,Th
15、e main influence on weather in the United States is the polar jet stream2, which brings in large low pressure systems from the northern Pacific Ocean. The Cascade Range, Sierra Nevada, and Rocky Mountains pick up most of the moisture from these systems as they move eastward. Greatly diminished by th
16、e time they reach the High Plains, much of the moisture has been sapped by the orographic effect as it is forced over several mountain ranges. However, once it moves over the Great Plains3, uninterrupted flat land allows it to reorganize and can lead to major clashes of air masses. In addition, moisture from the Gulf of Mexico is often drawn northward. When combined with a powerful jet stream, this can lead to violent thunderstorms, especially during spring and summer. S
