地形

全洲海拔200米以下的平原約占20%，海拔200-500米的平原和丘陵約占22%，海拔500米以上的高原和山地約占58%，全洲平均海拔700米。大陸地形的基本特征是南北走向的山脈分布于東西兩側(cè)與海岸平行，大平原分布于中部。地形明顯地分為三個(gè)區(qū)。

東部山地和高原：圣勞倫斯河以北為拉布拉多高原，以南為阿巴拉契亞山脈，地勢(shì)南高北低，海拔一般為300-500米。阿巴拉契亞山脈東側(cè)沿大西洋有一條狹窄的海岸平原，西側(cè)逐漸下降與中部平原相接。

中部平原：位于拉布拉多高原、阿巴拉契亞山脈與落基山脈之間，北起哈得孫灣，南至墨西哥灣，縱貫大陸中部。平原北半部多湖泊和急流，南半部屬密西西比河平原。平原西部為世界著名的大平原。

西部山地和高原：屬科迪勒拉山系的北段，從阿拉斯加一直伸展到墨西哥以南，主要包括三條平行山地，東帶為海拔2000-3000米以上的落基山脈，南北延伸5000千米，是北美洲氣候上的重要分界線；西帶南起美國(guó)的海岸山嶺，向北入海，形成加拿大西部的沿海島嶼，海拔一般為500-1000米；中帶包括北部的阿拉斯加山脈、加拿大的海岸山脈、美國(guó)的內(nèi)華達(dá)山脈和喀斯喀特嶺等。美國(guó)阿拉斯加州的麥金利山海拔6193米，為北美洲最高峰。

東帶和中帶之間為高原和盆地，大盆地底部海拔800-1300米，盆地南部的死谷低于海平面86米，為西半球陸地的最低點(diǎn)。北美洲平均海拔較高，地勢(shì)起伏較大，地形分為三大南北縱列帶：西部是高大的山系，中部是廣闊的平原，東部是低緩的高地。

火山與地震

北美洲西部沿海地區(qū)是太平洋沿岸火山帶的一部分。北美洲有活火山90多座，其中阿留申群島有28座，阿拉斯加有20座，中美洲有40多座。北美洲西部也是世界上地震頻繁和多強(qiáng)烈地震的地帶。

水系

北美洲的外流區(qū)域約占全洲面積的88%，其中屬大西洋流域的面積約占全洲的48%，屬太平洋流域的約占20%。除圣勞倫斯河外，所有大河都發(fā)源于落基山脈。落基山脈以東的河流分別流入大西洋和北冰洋，以西的河流注入太平洋。內(nèi)流區(qū)域（包括無流區(qū)）約占全洲面積的12%，主要分布在美國(guó)西部大盆地及格陵蘭島。密西西比河是北美洲最大的河流，按長(zhǎng)度為世界第四大河。其次為馬更些河、育空河、圣勞倫斯河和格蘭德河等。其它較為重要的河流有：科羅拉多河、俄亥俄河、哥倫比亞河等。

北美洲的河流上多瀑布，落差最大的瀑布是美國(guó)西部約塞米蒂國(guó)家公園的約塞米蒂瀑布，落差739米。尼亞加拉瀑布，落差54米，寬1160米。北美洲是個(gè)多湖泊的大陸，淡水湖總面積約40萬平方公里，居各洲首位。湖泊主要分布在大陸的北半部。中部高原區(qū)的五大湖：蘇必利爾湖、休倫湖、密歇根湖、伊利湖、安大略湖，總面積為245273平方公里，是世界上最大的淡水湖群，有“北美地中?！敝Q。其中以蘇必利爾湖面積最大，為世界第一大淡水湖。

地域分為東部地區(qū)、中部地區(qū)、西部地區(qū)、阿拉斯加、加拿大北極群島、格陵蘭島、墨西哥、中美洲和西印度群島九區(qū)。以白令海峽與亞洲為界，以巴拿馬運(yùn)河與南美洲為界。

東部地區(qū)

東瀕大西洋，海岸曲折，有很多港灣，北美洲大部分港口集中在這一地區(qū)，圣勞倫斯河谷以北為拉布拉多高原，海拔300-600米，多冰川湖，有湖泊高原之稱；以南為阿巴拉契亞山脈，一般海拔1000-1500米，山脈西側(cè)為阿巴拉契亞高原，山脈與大西洋問有狹窄的山麓高原和沿海平原。眾多短小湍急的河流經(jīng)山麓硬、軟巖層的交接處，形成瀑布，因而從紐約向西南至哥倫布一線有“瀑布線”之稱。本區(qū)是北美洲工業(yè)和農(nóng)業(yè)發(fā)展最早的地區(qū)，也是重要的工商業(yè)和金融中心。

中部地區(qū)

位于拉布拉多高原－阿巴拉契亞山脈與落基山脈之間，北起丘吉爾河上游，南達(dá)墨西哥灣，長(zhǎng)約3000千米，寬約2000千米的地區(qū)。是北美洲小麥、玉米、大豆、棉花最集中的產(chǎn)區(qū)及肉用畜牧業(yè)最發(fā)達(dá)的地區(qū)之一。

西部地區(qū)

由高大的山脈和高原組成，屬美洲科迪勒拉山系的北段，落基山脈是本區(qū)地形的骨架。多火山、溫泉，地震頻繁。內(nèi)地氣候干旱，以畜牧業(yè)為主，太平洋沿岸地區(qū)種植亞熱帶果品的園藝業(yè)十分發(fā)達(dá)，本區(qū)采礦業(yè)占重要地位，制造工業(yè)以飛機(jī)、造船等為重要。

阿拉斯加

阿拉斯加位于北美洲西北部。大陸部分，山脈分列南北，中部為育空高原，太平洋沿岸地區(qū)多火山，地震頻繁。礦物主要有石油、金、錫、銅、煤等。經(jīng)濟(jì)以采礦業(yè)、漁業(yè)和皮毛業(yè)為主。阿留申群島是阿拉斯加西南的一群火山島，地震頻繁。有皮毛獸的馴養(yǎng)和漁業(yè)。

加拿大北極群島

是北美大陸以北，格陵蘭島以西眾多島嶼的總稱。面積約160萬平方公里。人口稀少，主要居民是因紐特人。各島之間有許多海峽，其中巴芬島與拉布拉多半島之間的哈得孫海峽，是哈得孫灣通大西洋的海上交通要道。各島堅(jiān)巖裸露，多為海拔500-1000多米的山地，長(zhǎng)期受冰川作用，多冰川地形和冰川作用形成的湖泊。沿海平原狹窄，海岸曲折多峽灣。氣候嚴(yán)寒，年平均降水量不足300毫米。居民以捕魚和捕海獸為生。

墨西哥

位于北美洲的南部，是劍麻、銀膠菊等栽培植物的原產(chǎn)地。

中美洲

是中亞美利加洲的統(tǒng)稱，指墨西哥以南、哥倫比亞以北的美洲大陸中部地區(qū)。東臨加勒比海，西瀕太平洋，是連接南、北美洲的橋梁，包括危地馬拉、洪都拉斯、伯利茲、薩爾瓦多、尼加拉瓜、哥斯達(dá)黎加和巴拿馬。面積約52萬平方公里，人口約2984萬，全區(qū)以高原和山地為主。山地緊靠太平洋岸，屬美洲科迪勒拉山系的中段，最高處海拔達(dá)4000米以上，多火山，有活火山40余座，地震頻繁（詳見中美諸國(guó)圖幅文字說明）。中美洲是甘薯的原產(chǎn)地。

西印度群島

位于大西洋及其屬海加勒比海、墨西哥灣之間。15世紀(jì)末，意大利航海家哥倫布到此，誤認(rèn)為這里是印度附近的島嶼因位于印度以西的西半球，便稱為西印度群島，一直沿用。包括巴哈馬國(guó)、古巴、牙買加、海地、多米尼加共和國(guó)、安提瓜和巴布達(dá)、多米尼克國(guó)、圣盧西亞、圣文森特和格林納丁斯、巴巴多斯、格林納達(dá)、特立尼達(dá)和多巴哥、圣基茨和尼維斯等，此外還包括美國(guó)、英國(guó)、法國(guó)和荷蘭的十多個(gè)屬地。面積約24萬平方公里。

這些群島分為三大組：一、巴哈馬群島，由14個(gè)較大的島嶼、700個(gè)小島和暗礁以及2400個(gè)環(huán)礁組成。島上主要居住黑種人。各島海拔最高不到60米。屬熱帶雨林氣候。二、大安的列斯群島，包括古巴、海地、牙買加、波多黎各諸島及其附屬島嶼。一半以上為山地。海地島和波多黎各島地震頻繁。各島北部屬熱帶雨林氣候，南部屬熱帶草原氣候。三、小安的列斯群島，包括背風(fēng)群島、向風(fēng)群島和委內(nèi)瑞拉北面海上許多島嶼。多為火山島，地震頻繁。屬熱帶雨林氣候。

格陵蘭島

位于北美洲東北，介于北冰洋與大西洋之間。面積約217.56萬平方公里，是世界第一大島。常被稱為格陵蘭次大陸。人口80%是格陵蘭人。全島約4/5的地區(qū)處于北極圈內(nèi)，面積84%為冰雪所覆蓋。中部偏東最高海拔3300米，邊緣地區(qū)海拔1000-2000米。氣候嚴(yán)寒。礦物有冰晶石、鐵、鋅、鉛、鋯、褐煤等。在南部發(fā)現(xiàn)鉬、鈾、釷等礦物。著名的動(dòng)物有麝牛、馴鹿、北極熊等，居民以漁業(yè)為主，南部地區(qū)有少量牧羊業(yè)、魚類加工、采礦業(yè)尤以南端冰晶石的開采最重要。首府戈特霍布（努克）。

terrain

The plain below 200 meters above sea levelaccounts for about 20%, the plain and hills between 200 and 500 meters abovesea level accounts for about 22%, and the plateau and mountains above 500meters account for about 58%, with an average elevation of 700 meters. Thecontinental terrain is characterized by north-south mountain ranges runningparallel to the coast on the east and west sides, and the Great plains in themiddle. The terrain is clearly divided into three zones.

Eastern mountains and Plateaus: TheLabrador Plateau to the north of the St. Lawrence River, the AppalachianMountains to the south, the terrain is high in the south and low in the north,and the altitude is generally 300-500 meters. There is a narrow coastal plainalong the Atlantic Ocean on the eastern side of the Appalachian Mountains,which gradually descends to meet the central Plain on the western side.

Central Plain: Between the LabradorPlateau, the Appalachian Mountains and the Rocky Mountains, extending fromHudson Bay in the north to the Gulf of Mexico in the south through the middleof the continent. The northern half of the plain is covered with lakes andrapids, while the southern half is covered by the Mississippi River plain. Thewest of the plains is the world famous Great Plains.

Western mountains and plateaus: It is thenorthern section of the Cordillera system, stretching from Alaska to the southof Mexico, mainly including three parallel mountains. The eastern belt is theRocky Mountains with an altitude of 2,000-3,000 meters above sea level,extending 5,000 kilometers from north to south, which is an important dividingline of North America's climate. The western belt starts from the coastmountains of the United States in the south, and enters the sea in the north toform the coastal islands of western Canada. The altitude is generally 500-1000meters; The mesosphere includes the Alaska Range in the north, the Coast Rangein Canada, and the Sierra Nevada and Cascade Ridge in the United States. MountMcKinley in Alaska, the United States, is 6,193 meters above sea level, thehighest peak in North America.

Between the eastern belt and the middlebelt, there are plateaus and basins. The bottom of the Great Basin is 800-1300meters above sea level, and Death Valley in the southern part of the basin is86 meters below sea level, the lowest point of land in the Western hemisphere.North America has a higher average altitude and larger terrain fluctuations.The terrain is divided into three major north-south vertical belts: the west isa tall mountain system, the middle is a broad plain, and the east is a lowplateau.

Volcanoes and earthquakes

The coastal region of western North Americais part of the Pacific Ring of Fire. There are more than 90 active volcanoes inNorth America, including 28 in the Aleutian Islands, 20 in Alaska and more than40 in Central America. The western part of North America is also the area ofthe world where earthquakes are frequent and strong.

drainage

The outflow area of North America accounts forabout 88% of the whole continent, of which the area belonging to the Atlanticbasin accounts for about 48% of the whole continent, and the area belonging tothe Pacific basin accounts for about 20%. All major rivers, except the St.Lawrence, rise in the Rocky Mountains. Rivers east of the Rockies drain intothe Atlantic and Arctic Oceans, respectively, while those west drain into thePacific Ocean. The inflow area (including the no-flow area) accounts for about12% of the whole continent, mainly distributed in the Great Basin of thewestern United States and Greenland. The Mississippi River is the largest riverin North America and the fourth longest in the world by length. It is followedby the Mackenzie River, Yukon River, St. Lawrence River and the Rio GrandeRiver. Other important rivers are the Colorado River, the Ohio River, and theColumbia River.

There are many waterfalls on rivers inNorth America. The largest waterfall is Yosemite Falls in Yosemite NationalPark in the western United States, which drops 739 meters. Niagara Falls, 54meters wide, 1160 meters wide. North America is a continent with many lakes.The total area of fresh water lakes is about 400,000 square kilometers, rankingfirst among all continents. Lakes are found mainly in the northern half of thecontinent. The Great Lakes in the central Plateau Region: Lake Superior, LakeHuron, Lake Michigan, Lake Erie, Lake Ontario, with a total area of 245,273square kilometers, is the largest group of freshwater lakes in the world, knownas the "North American Mediterranean". Lake Superior is the largestfreshwater lake in the world.

The region is divided into nine regions:Eastern region, Central Region, Western region, Alaska, Canadian ArcticIslands, Greenland, Mexico, Central America and West Indies. It is bounded bythe Bering Strait and Asia, and by the Panama Canal and South America.

The eastern region

East Atlantic, coast twists and turns,there are many harbors, most ports in North America concentrated in this area,the St. Lawrence Valley north for the Labrador plateau, 300-600 meters abovesea level, more glacial lake, lake plateau said; South of the AppalachianMountains, generally 1000-1500 meters above sea level, the west side of themountains for the Appalachian plateau, the mountains and the Atlantic Oceanhave narrow foothill plateau and coastal plain. Many short, fast-flowing riverspass through the hard and soft rock at the foot of the mountain to form awaterfall, so the southwest from New York to Columbus line called the"waterfall line." This region is North America's earliest industrialand agricultural development area, is also an important industrial, commercialand financial center.

The central region

Located between the Labrador Plateau,Appalachian Mountains and Rocky Mountains, from the upper Churchill River inthe north to the Gulf of Mexico in the south, an area about 3,000 kilometerslong and 2,000 kilometers wide. It is one of the most concentrated producingareas of wheat, corn, soybean and cotton in North America and one of the mostdeveloped areas of meat animal husbandry.

In the western region

Composed of tall mountains and plateaus, itis the northern section of the American Cordillera system, and the RockyMountains are the skeleton of the terrain in this area. Many volcanoes, hotsprings, frequent earthquakes. Inland CLIMATE IS DRY, mainly ANIMAL husbandry,THE Pacific COAST area planting SUBTROPICAL fruits of HORTICULture is verydeveloped, mining plays an important role in this area, manufacturing industryto aircraft, shipbuilding and other important.

Alaska

Alaska is in the northwest of NorthAmerica. The mainland part, the mountains are divided into north and south, thecentral Yukon Plateau, the Pacific coast region more volcanoes, earthquakes arefrequent. The main minerals are petroleum, gold, tin, copper, coal and so on.The economy is dominated by mining, fishing and fur industry. The AleutianIslands are a group of volcanic islands southwest of Alaska that are prone toearthquakes. The domestication and fishing of furry beasts.

Canadian Arctic Islands

A group of islands north of the NorthAmerican continent and west of Greenland. The area is about 1.6 million squarekilometers. The population is small and the main inhabitants are Inuit. Thereare many straits between the islands, among which the Hudson Strait betweenBaffin Island and Labrador Peninsula, is the Hudson Bay through the AtlanticOcean maritime traffic arteries. The exposed hard rocks of each island aremostly mountainous areas with an altitude of 500-1000 meters. They are lakesformed by long-term glaciation, multi-glacial topography and glaciation. Thecoastal plain is narrow and the coast is tortuous with fjords. The climate iscold, the average annual precipitation is less than 300 mm. The inhabitantslive by fishing and catching sea animals.

Mexico

Located in the southern part of NorthAmerica, is the origin of sisal, guayule and other cultivated plants.

Central America

It is a general term for Central America,which refers to the central part of the American continent south of Mexico andnorth of Colombia. Facing the Caribbean Sea to the east and the Pacific Oceanto the west, it is a bridge connecting North and South America, includingGuatemala, Honduras, Belize, El Salvador, Nicaragua, Costa Rica and Panama.With an area of about 520,000 square kilometers and a population of about 29.84million, the region is dominated by plateaus and mountains. The mountain isclose to the Pacific coast, and belongs to the middle part of the Cordilleramountain system in America. The highest point is more than 4,000 meters abovesea level.