Having almost half of the mainland, the country has a huge set of natural climatic conditions. On the territory of the United States can be found both hot dry deserts and wet evergreen forests, both harsh mountain landscapes and endless expanses of overgrown grass of plains or dense forests. Due to these reasons, the country’s territory is usually divided into eight natural provinces, combined for simplicity of four zones: mountainous areas of Cordiller, central plains, Appalachi and coastal plains, highlighting Alaska and Hawaiian Islands in separate natural complexes.
About half of the territory of the United States occupies the mountain ranges, plateaus and plateaus of the vast system of Cordiller, stretching from the north to south throughout the west of the country, from Alaska to California and New Mexico. The length of the mountain ranges is about 1,700 km with a maximum width of up to 1600 km (almost a third of the US Square, the rest – Appalachi and other old mountains, often weathered to the state of high hills or plateau). In a complex system of ridges and intergigurgy Kotlovin Cordiller, three belts are highly distinguished – East, or the Rocky Mountains belt (Sacramento Mountains, Sangre de Cristo, an advanced ridge, Big Horn and others, the highest point – Mount Elbert, 4399 m); Western, or Pacific Belt (Coast Rats, Sierra Nevada, Cascade Mountains, Lower California and Other, High Point – Whitney Mount, 4418 m) and the so-called inner belt, consisting of high plateau (Colorado, Utah and DR.) and individual mining arrays separated by deep bars ("Parks") and valleys (here is the lowest point of the mainland – the valley of death, – 85 m). On the eastern bud of the Rocky Mountains and in the southern part of the coastal ridges (San Andreas Rift) there is a high seismic activity, and in the cascading mountains there are valid and sleeping volcanoes (Rainier, Hood, Olympus and others.).
The nature of the mountain areas is extremely diverse – thick mixed forests and sections of grassy prairies are abundant on the eastern and northern slopes, and the mountain forests, alpine meadows and waste, the tops of the mountains are crowned with powerful glaciers and snowflies (the total area of the glaciation of about 67 thousand. kv. km), and in intermountain basins the vegetation is dry, close to the Mediterranean type. At the same time, in the southern regions of intergores there are extensive areas of rocky deserts and semi-deserts (Sonora, Arizona, Mojave, a desert of a large salt lake and DR.), extensive salt marshes, and in the north – evergreen mountain forests. From the slopes of the mountains take the beginning of the origins of numerous rivers – Ampku, Arkansas, Klamat, Colorado, Colombia, Missouri, Platt, Rio Grande, Chayenne and others (mountain areas are a natural watershed between the atlantic and quiet oceans pools), and in an abundance in the inner belt There are real regions (large pool, Wpadina Solton, the desert of a large salt lake and others.) with dried lakes covered with thick peel.
Central plains occupy an area of more than 2.9 million square meters. km and stretch through the entire central part of the United States from north to south. The surface relief here is an elevated plain, with a large number of hilly areas and extensive valleys of rivers. However, this area is not so uniform, as it seems – in the West, arrays of the Prairi, Missouri, Llano-Estakado and EduardS (height 700-1800 m, width – up to 800 km), and in the east – famous great plains with extensive prairies and agricultural regions in the center and in the north and no less extensive empty and erosion semi-derangements "Bedlendz" in the southern part. Eastern stretching strip of internal elevations (Plateau Ozark, Springfield and Salem, as well as low mountains Boston and Woshito), and even east – fertile central plains, moving in the north of northern plains around Lake Ontario, Erie, Huron and Michigan.
The Eastern Coast of the country framed the system of old towns of Appalachi, stretching from the north-east to the southwest to 2600 km (the highest point – Mitchell Mountain in the Black Mountains Mountains, 2037 m). The Appalach system is also heterogeneous: the main array is formed by two plateau – Alleghan in the north and Cumberland in the south, from the east of the Pidmont Plateau and the Mountain System Bloj Ridge, in the north – the mountains of Adirondak (the highest point – Mounta Marti, 1629 m) and the elevations of New England (White Mountains and Green Mountains), and in the West – the Big Appalacian Valley (Great Velley) and the area of numerous small ridges and river valleys of the left tributaries of Mississippi. This mountain system is one of the oldest on the planet, so many slopes are strongly smoothed by erosion and thickly enclosed with broad and coniferous forests, and numerous rivers form a complex network of fertile valleys.
From the east and the south, the Appalach area is surrounded by coastal plains stretching the extensive strip throughout the Atlantic coast of the United States to the Mexican border in the south. Relatively narrow (from 160 to 320 km) angel plain, which lies between the east slopes of the Appalach and the shore of the ocean, almost all of its entire length disseminated by the valleys of numerous rivers. Here are the largest cities of the country and many agricultural areas. Primexican plain is significantly wider (up to 970 km, and its northern part is deeply deeply in the Mississippi Valley almost to Lake Michigan, forming a part of the central plains). It is also dressed with numerous river valleys, and its southern part is an extended strip of countless mouths and estuariums, the largest of which is a huge Delta Mississippi. In the southeastern part of the region deep into the sea issued a low-aluminated Peninsula Florida, almost entirely covered with wetlands and subtropical vegetation of the Mediterranean type.
Alaska is located on the very northwest mainland and is formed by the Northern Szř.), as well as numerous apparent and moraine plains constituting extensive smooth spaces between the mountains. In the Alaskan ridge there is the highest point of North America – Mac-Kinley Mountain (Denali, 6194 m). The continuation of the mining systems is the numerous island groups (Alexander Archipelago, Aleuta Islands, Promit Island, Kadyak, St. Lawrene, St. Matvey, and others.) far away in the waters of the Pacific Ocean. In the north lies an extensive arctic lowland adjacent to the Arctic Ocean. On the Pacific Coast of Alaska, the climate is moderate, marine, thick coniferous forests and mountain meadows grow here, in the northern regions, climatic conditions relate to the Arctic and subarctic continental type, because the harsh zone of tundra vegetation and the Arctic desert extended here.
The chain of the islands of the Hawaiian archipelago located in the northern part of the Pacific Ocean, formed the activities of numerous volcanoes. All the largest islands of the group (Hawaii, Kaolaw, Lana, Oahu, Maui, Moloka, Kauai, etc.) Gorists and are formed by the slopes of volcanoes (often one island is complex at several low volcanoes of different ages). North-Western Islands are coral atolls crowded by the highest underwater volcanoes (some of them from the foot to the tops are superior to Everest at least one and a half times), but the islands of this group are towering over the water no more than 20-40 meters. The soft marine climate and rich volcanic soils led to the formation of richest natural complexes of tropical type here, in which each second living being is not found anywhere else on the planet, but the human intervention has led to a noticeable decoup of local flora and fauna.
Dangerous plants and animals
A separate danger represents some representatives of flora and fauna, especially when visiting national parks. In Alaska and in other northern states, large populations of large animals dangerous for a person in a certain time live. In many cities of these regions, it is often possible to see the Bear Grizzly, in containers for waste, wolves and sacking, desiccately walking along the outskirts of the settlement, as well as boars and salts, grazing on suburban fields and in Mescalese. When visiting wildlife, all food must be reliably pack, so that it is not visible and if possible did not spread odors. In some parks, food reserves even recommend hanging on trees in special packages and in no case do not store them in a car or tent, as it can easily attract the attention of large animals, up to bears, which in many parks have long moved to food "from the table of tourist". Accordingly, the risk to meet with them when visiting protected areas is very high, therefore it is always worth listening to the advice of guides and conductors, well-trained behavior in the event of a collision with these animals, and not go beyond the limits of recommended zones. Even Surki, Susliki and meadow dogs can represent a certain danger, since they are natural pedders of infectious diseases (for example, meadow dogs have recently become infected with plague).
When visiting the national parks, it is necessary to have repeated repairee, since the number of different bloodsowing insects here is no less than in our forests, and the South State Mosquitoes are not only able to transfer various diseases, but their bites are also very painful. In the eastern states, the pebble disease is common (tick-boring borreliosis), and tick bites are not uncomfortable even in ordinary city parks. In Texas, we frequent meetings with poisonous snakes (in many places of the likely cluster of these animals, warning signs are exhibited, but they are common everywhere). In Nevada and other deserted states, scorpions and poisonous spiders represent a special danger.
In the southern semi-desert areas there are quite a few plants whose spines and spikes can cause serious damage to unprotected human skin. A separate danger has recently been Sumy Poison (Rhus Toxicodendron, Poison Ivy) and toxicodendron (Toxicodendron Radicans, Poison Oak), in abundance growing on the roads and wastehouses across the country. Burns applied by the leaves of these plants are very painful and require long-term treatment with hormones and antibiotics.
In marine waters around Florida, portuguese ships are of a special danger (physalia; human transfers) floating on the surface of water. They are most similar to giant jellyfish with fringe long (up to 10 m) tental, who can apply very painful and often dangerous to health burns.
Care should also be taken when swimming in the open sea off the coast of Florida and Louisiana. In some parts of the sea, the water is contaminated with oil waste from the nearest oil platforms and regularly passing tankers from the coasts, in other many quite aggressive marine inhabitants like a shark or barracud. Swimming on unequipped western states is also extremely careful because in these areas the cold oceanic flows are often suitable for the coast itself, the excitement is strong enough, and the stony shores are quite uncomfortable for entering and entering.