Geography

Sinkholes are common in humid areas where limestone forms the underlying bedrock. Geologists refer to these areas as karst. Sinkholes are formed when ground water reacts chemically with the limestone and dissolves it over time, causing either a depression or a hole in the ground. Large holes result when the dissolved limestone is part of … Read more

The Gulf of Mexico part of the Atlantic Ocean. By definition, a gulf is a part of a sea or ocean that extends into land. The Caribbean Sea is also part of the Atlantic Ocean. Three times more water from U.S. rivers drains into the Atlantic Ocean than into the Pacific. The Gulf of Mexico … Read more

In Florida, where almost 10 people each year, on average, are killed by lightning strikes from thunderstorms. Most of the victims are men, and most are on golf courses. Nearly five people on average are killed each year by lightning in North Carolina and Texas, two other states where golfers and thunderstorms frequently mix. There … Read more

The Ten Deadliest Tornadoes in the United States were: Missouri, Illinois, Indiana, March 18, 1925, 695 deaths. Natchez, Mississippi, May 6, 1840, 317 deaths. St. Louis, Missouri, May 27, 1896, 255 deaths. Tupelo, Mississippi, April 5, 1936, 216 deaths. Gainesville, Georgia, April 6, 1936, 203 deaths. Woodward, Oklahoma, April 9, 1947, 181 deaths. Amite, Louisiana, … Read more

There are five major mountain ranges in the United States: the Appalachian Mountains in the East; the Rocky Mountains in the Southwest and West, from Colorado to the Canadian border and beyond; the Cascade Mountains in the Pacific Northwest; the Sierra Nevada in the far West; and the Alaska Range, a segment of the Coast … Read more

For the 48 conterminous states, the geographic center is near Lebanon, Kansas. If you take Alaska into account, the geographic center of the United States becomes a point near Castle Rock, South Dakota. In 1918 a monument was erected at the site to mark the spot. In 2000, the population of Lebanon, Kansas was 303. … Read more

The Appalachian Mountains are not as tall and jagged as the Rocky Mountains because they are so much older and have been worn down by weathering and erosion over millions of years. The Appalachians run for about 2,000 miles (3,218 km) from Newfoundland, Canada, through Maine all the way south to central Alabama. They are … Read more

Mount McKinley, also called Denali, in Alaska is the tallest mountain in the United States, at 20,320 feet (6,193 m). On a clear day the peak can be seen from as far as 250 miles (402 km) away. The next 16 highest peaks in the United States also are in Alaska. Number 18 is Mount … Read more

The Appalachian Trail, often called the A.T., is a footpath that runs for 2,167 miles (3,488 km) along the crests and through the valleys of the Appalachian Mountains. The trail’s northern end is Katandin, Maine. From there it passes through New Hampshire, Vermont, Massachusetts, Connecticut, New York, New Jersey, Pennsylvania, Maryland, West Virginia, Virginia, Tennessee, … Read more

Denali is the ancient Indian name for Mount McKinley, meaning “The Great One” or “The High One.” It is in Denali National Park and Preserve, about 130 miles (209 km) north of Anchorage, Alaska. The mountain was renamed for President McKinley in 1896. Mount McKinley is a granitic pluton which has been uplifted by tectonic … Read more

At 282 feet (85 m) below sea level, the lowest point in the United States is Bad Water, in Death Valley, California. At Badwater, significant rainstorms flood the valley bottom periodically, covering the salt pan with a thin sheet of standing water. The sign marking “sea level” on the cliff above Badwater is a popular … Read more

An avalanche is defined as an extremely rapid slide and fall of snow, rocks, and trees. Between 1985 and 1998 a total of 240 people died in avalanches in the United States. The most accidents occurred in Colorado, followed by Alaska, Utah, and Montana. Only a few people died within ski area boundaries, most who … Read more

Phoenix, Arizona, on average, experiences sunny or partly cloudy skies 81 percent of the days in a year. As a result, Phoenix, Arizona is known as the sunniest city in the United States. Phoenix, Arizona is the fifth most populated city in the United States, making it the most populous state capital. Following Phoenix as … Read more

Chicago may be called the Windy City, but the nation’s windiest city is Cheyenne, Wyoming, where the average annual wind speed clocks in at 12.9 miles (21 km) per hour. Chicago, at 10.4 miles (17 kin) per hour, is calm compared to Cheyenne and these other cities, where average winds speeds range from 12.6 miles … Read more

Tornadoes usually form in the spring when thunderstorms create strong vertical wind shears that cause updrafts of wind to rotate at high speeds. This violently rotating column of wind extends from the base of the thunderstorm cloud to the ground. On the ground, the tornado’s swirling winds gather up dust and debris, which is why … Read more

Since 1980, there have been more than 44 weather related disasters in which damages and costs have exceeded $1 billion. The worst year was 1998, when seven such disasters took place. Here are the top 10: Drought and heat wave, central and eastern states, 1980: $44 billion, 10,000 deaths Drought and heat wave, central and … Read more

Los Angeles, California, has the highest relative humidity in the United States, where the average July afternoon humidity reaches 68 percent. Not much better are runner ups San Juan, Puerto Rico (67 percent); San Diego, California (66 percent); Juneau, Alaska (66 percent); New Orleans, Louisiana (66 percent); Miami, Florida (63 percent); Mobile, Alabama (62 percent); … Read more

Tornado Alley generally extends from South Dakota through Kansas and Oklahoma into northern Texas. This area is known for its high average number of tornadoes per year, about 20. But tornadoes can occur in all 50 states. Oklahoma City is hit by more tornadoes than any city in the nation, a total of 103 struck … Read more

It is difficult to directly measure ground speeds of tornadoes. But scientists managed to determine that a tornado that passed near Bridge Creek, Oklahoma, on May 3, 1999, was traveling at 318 miles (512 km) per hour, the highest winds ever recorded on the Earth’s surface. Bridge Creek was one of several communities hardest hit … Read more

A tornado that rampaged for 219 miles (353 km) through Missouri, Illinois, and Indiana in March 1925 is believed to have killed nearly 700 people. In one town alone, Murphysboro, Illinois, at least 234 people died. That record still stands for the most fatalities in a single U.S. town or city due to a tornado. … Read more

Most tornadoes, but not all, in the Northern Hemisphere rotate counterclockwise, or cyclonically. Most tornadoes in the Southern Hemisphere, in Australia for example, rotate clockwise, or anticyclonically. Every once in a while, an anticyclonic tornado is seen in the United States, one struck near Sunnyvale, California, in 1998. But usually they take the form of … Read more

Yes, it can snow in the desert, in fact, snow has fallen in almost every part of the United States at one time or another. The most snow ever reported in Phoenix, Arizona, was 1 inch (2.5 cm), an event that has happened there twice, the first time on January 20, 1933, and the second … Read more

The National Weather Service says that an average of 105 snow producing storms affect the United States each year. Most last from 2 to 5 days and bring snow to parts of several states. The snowiest city in the United States is Sault Ste. Marie, Michigan. It gets an average of 117 inches (297 cm) … Read more

Seattle has a reputation for rainy weather, but it’s not the rainiest place in the United States. For example, New Orleans, Louisiana, and Mobile, Alabama, each average more than 61 inches (155 cm) of rain a year, followed by Miami, Florida (56 in/142 cm) and Juneau, Alaska (54 in/137 cm). Seattle receives an average of … Read more

In the past 50 years or so, Pennsylvania tops the list of states experiencing extensive damage from flooding, followed by California, Louisiana, Iowa, Texas, and Missouri, in that order. Floods result from a volume of water, such as a river or lake, which overflows or breaks levees. The word “flood” comes from the Old English … Read more

The record for the most abrupt temperature change in the United States is held by Spearfish, South Dakota, where it took just 2 minutes to warm up from -4° to 45° Fahrenheit on August 29, 1936. The U.S. location holding the record for the greatest range of temperatures over a 24-hour period is Browning, Montana, … Read more

When a tropical cyclone reaches a wind speed of 39 miles (63 km) per hour, the World Meteorological Association assigns it a name from one of six lists of names it rotates yearly. If a hurricane is especially deadly or causes extensive damage, its name is “retired” and a new name starting with the same … Read more

The fastest wind speed on record, not counting tornadoes, in the United States and the world took place on Mount Washington, in New Hampshire, on April 12, 1934. That day, the wind speed was recorded at 231 miles (372 km) per hour. This record is also the world record for wind gusts. Mount Washington also … Read more

The coldest day in the United States happened on January 23, 1971, in Prospect Creek, Alaska, when the temperature dipped to -79.8° Fahrenheit. Every U.S. state except one has experienced a day in which the temperature fell below 0° Fahrenheit. The exception is Hawaii, where the lowest temperature on record is 12° Fahrenheit, on May … Read more

The hottest day on record in the United States happened on July 10, 1918, in Greenland Ranch, California (in Death Valley), when the thermometer reached 134° Fahrenheit. Death Valley is an arid desert basin that covers parts of eastern California and western Nevada. At one time or another, every U.S. state has recorded a high … Read more

Officially, the Atlantic hurricane season runs from June 1 to November 30. But most hurricanes develop between August and October, with the largest number occurring from early to mid-September. In September 1900, the worst natural disaster ever in the United States, the Galveston hurricane, destroyed most of the city of Galveston, Texas. At least 8,000 … Read more

Both a hurricane and a typhoon are names for strong tropical cyclones. The regional name for a tropical cyclone that forms in the northwestern Pacific Ocean west of the dateline is typhoon. Hurricane is the regional name for a tropical cyclone that forms in the Atlantic Ocean, the Gulf of Mexico, the Caribbean Sea, the … Read more

Hurricanes form in both the Atlantic and the Pacific Ocean basins, in tropical or subtropical regions. Because hurricanes tend to move toward the west or the northwest, they usually move toward the U.S. East Coast but move away from the U.S. West Coast. Another reason why hurricanes never strike the U.S. West coast is that … Read more

Is it usually warmer in New York City than in rural New Jersey because cities tend to be warmer than the surrounding countryside. This is known as the urban heat island phenomenon. Cities are warmer in summer and winter because they are full of concrete and asphalt, which retain heat better than soil and fields. … Read more

Also called a nor’easter, a northeaster type of winter storm blows into North America from the northeast and brings strong winds and precipitation to New England and the Mid-Atlantic states. They occur most often between September and April. A Northeaster is usually described as a low pressure area whose center of rotation is just off … Read more

Santa Anas are similar to chinooks. These winds blow from Utah and Nevada over the Sierra Nevada mountains and into southern California. The air they bring is very dry, which causes vegetation to dehydrate, putting the region at risk for wildfires. Winds in Hawaii have their own special names: Kona is a southwesterly wind that … Read more

A Chinook is a term used to describe a type of wind that occurs in the Rocky Mountains. Winds generally blow from west to east across the United States. Chinooks often result when air from the west blows over and down the eastern sides of the Rocky Mountains. These winds can gust up to 100 … Read more

Average annual temperatures in the United States have increased by almost 1° Fahrenheit since the late 1800s. Half of that increase occurred in just the past 40 years. In fact, the four warmest years since 1860 all occurred during the 1990s. But it’s not getting warmer everywhere; in fact, parts of the southeastern United States … Read more

Latitude is only one factor of several that determine climate in any particular region. San Francisco’s position between 30° and 40° latitude and its location on the western side of the North American continent place it in the climate subcategory called Mediterranean. People living there experience warm, dry summers and mild, wet winters. Washington, D.C.’s, … Read more

The term weather usually refers to what is happening in the atmosphere at a specific location on a day to day basis. Climate refers to weather conditions that tend to occur in an area over a long period of time. Climates in the United States vary widely. In fact, they include five of the six … Read more

El Nino refers to a cycle that occurs every few years in which warm water accumulates in the eastern part of the Pacific Ocean around the equator. Some scientists think this cycle may be caused by changes in trade wind patterns. During an El Nino year, places such as Australia, North America, South America, and … Read more

During an El Nino year in the continental United States, winter temperatures are generally warmer than normal in the North and cooler than normal in the South. During the winter of a La Nina year, the southeastern states generally have warmer winter weather than normal, while the northwestern states are cooler than normal. El Nino … Read more

Global warming refers to the theory that the Earth’s atmosphere, specifically, the troposphere or lower atmosphere, is retaining more heat because of an increase in the amount of greenhouse gases. These gases include carbon dioxide, methane, and nitrous oxide, and together they prevent about 30 percent of the heat that leaves the Earth’s surface from … Read more

In 2000, a total of 164 million computers were in use in the United States, the largest number in the world. Japan, Germany, Great Britain, France, and Italy, in that order, were the next-largest computer users. The world total was 579 million computers. It is estimated that in 2010, more than 80%, or 250 million … Read more

High speed trains, often called bullet trains, are being planned in several regions of the United States. A high speed train is defined as one that can run between 150 and 320 miles per hour (242 and 515 km/hr). Amtrak’s Acela trains travel at speeds up to 150 miles per hour and are now connecting … Read more

The United States exports a large portion of its farm products to other countries. For example, U.S. farmers are the world’s leading exporters of corn, in 1999 they sold more than one fifth of the corn they grew to other countries. The United States is the world’s second largest exporter of wheat, the countries of … Read more

More than 6 of every 10 Internet users in the world live in the United States. But if you consider the percentage of a country’s population that uses the Internet, the United States ranks fourth, behind Canada, Sweden, and Finland. In 2000, about 280 million people worldwide were using the Internet. In 2010, there were … Read more

Believe it or not, most people in the world do not have telephones in their homes. For example, according to the World Bank, only one of every five people in Russia has a phone line. If you lived there, you’d have to wait an average of five years to get phone service. The wait is … Read more

The United States consumes more electricity than any other country in the world. The United States generates and consumes about one fourth of all the electricity worldwide. China is second, consuming about one tenth of the world’s electricity, followed by Russia, Japan, Germany, India, and Canada, in that order. The average person in the United … Read more

The United States does not have more working women than any other country. The United States is in sixth place, with about 71 percent of women working for pay. Iceland, Sweden, Norway, Denmark, and Finland all have a higher percentage of women who work for pay. Of the world’s 6 billion people, nearly 1 billion … Read more

The United States is the world’s leading air polluter, responsible for one fourth of all carbon dioxide emissions. Carbon dioxide emissions result from burning fossil fuels, such as gasoline, oil, natural gas, and coal. China is the world’s second worst air polluter, accounting for 12 percent of carbon dioxide emissions, followed by Russia, Japan, Indonesia, … Read more

About one fifth of electricity generated in the United States comes from nuclear power plants. But most of the electricity we use, about one half, is made by burning coal. It’s no coincidence that the United States is the world’s leading coal producer. Natural gas and petroleum generate another one fifth of U.S. electricity, and … Read more

The United States has nearly 4 million miles (6.4 million km) of roads, most of which are paved. That is more than five and a half times China’s 719,000 miles (1.16 million km) of roads. China has about the same amount of land area as the United States. If every family car and truck in … Read more

The United States is the richest country in the world by GNP, and has held the position for a while now. Economists measure a country’s wealth by looking at the value of the goods and services it produces each year. They call this the GNP, which stands for gross national product. The United States had … Read more

Americans born today can expect, on average, to live about 77 years. A person born in sub-Saharan Africa today can expect to live only 49 years. People born in Japan can expect to live the longest, to age 80, while people in Iceland, Sweden, and Switzerland will live to age 79, on average. As a … Read more

The population density of the United States is 77 people per square mile. The most densely populated country in the world is Monaco, with more than 55,000 people per square mile. Of course, Monaco is one of the world’s smallest countries, at just a little over 0.5 square mile (1.3 sq km). The country where … Read more

The U.S. Census Bureau predicts that 338 million people will be living in the United States by 2025, about 57 million more people than in 2000. One reason for this growth is that each year nearly 1 million immigrants come to the United States to live. If it weren’t for these immigrants, the U.S. population … Read more

The width of the United States depends on whether Alaska or Hawaii is included. Measured from the farthest points west and east in the conterminous United States, meaning the 48 states that have a common boundary, which are West Quoddy Head, Maine, and Point Arena, California, the United States is 2,892 miles (4,656 km) wide. … Read more

The United States is the fourth largest country in the world in land area, with 3,678,900 square miles (9,565,140 sq km). The largest country in the world, with 6,592,812 square miles (17,141,311 sq km), is Russia; it is almost twice as big as the United States. Canada ranks number two in size (3,831,000 sq mi/9,960,600 … Read more

The southernmost point of the 50 states is Ka Lae, Hawaii, at 18°55′ north latitude and 155°41′ west longitude. Also known as South Point, Ka Lae is the southernmost point of the Big Island of Hawaii. Ka Lae is the site of one of the earliest Hawaiian settlements, and it is believed that it is … Read more

After a great deal of discussion, Great Britain, which governed British Canada until 1931, and the United States finally agreed in 1846 to make the 49th parallel the western part of their boundary. This boundary line starts in Minnesota and extends west to what is now Washington State. There was only one problem: the 49th … Read more

Embark on a geographical journey from the southern tip of Texas to the Canadian border, exploring the vast distance that spans North America. Uncover the diverse landscapes along this expansive route. Key Takeaways: Discover the impressive length of the journey from the southern tip of Texas to the Canadian border. Explore the diverse terrains and … Read more

In 2000, the United States was the world’s third largest nation, with more than 281 million people. China was more than four and a half times larger. Here were the top 10 countries in population at the turn of the century: China 1.3 billion India 1 billion United States 281 million Indonesia 212 million Brazil … Read more

Just two U.S. cities, in metropolitan area population, were in the world’s top 10 cities in size in 2000, according to the United Nations: New York and Los Angeles. The figures for New York and Los Angeles are smaller than the U.S. Census Bureau estimates. This is because different organizations come up with different numbers … Read more

More than 4 million babies, about 11,000 a day, are born each year in the United States. That seems like a lot, until you learn that more than 137 million babies are born in the world each year. Only 1 of every 20 people in the world today lives in the United States, even though … Read more

The northernmost point of the 50 United States is Point Barrow, Alaska, which lies at 71°23′ north latitude, and 156°29′ west longitude. 90° north latitude is at the North Pole. The distance from Point Barrow to the North Pole is 1,122 nautical miles, and it marks the limit between the Chukchi Sea on its western … Read more

The United States is a country located on the North American continent in the Western Hemisphere. It is also located in the Northern Hemisphere. The United States is one of 191 independent countries in the world. The state of Hawaii is an archipelago in the mid-Pacific. The United States also has several territories in the … Read more

If the Antarctic ice sheet melted, the sea level around the world would rise about 220 feet (67 meters), the height of a 20-story building. About 90 percent of the world’s ice is held in that ice sheet. The large volume of ice on the continent of the Antarctic stores around 70% of the world’s … Read more

Antarctica is the coldest place on earth. The world’s lowest recorded temperature was at Vostok Station on July 21, 1983, when the thermometer dropped to -128.6° F (-89.2° C). Year round in Antarctica, the temperature rarely rises above freezing. Antarctica is colder than the Arctic because the continent is more than 3 kilometers (2 miles) … Read more

The use of the name “Antarctica” for the continent is attributed to the Scottish cartographer John George Bartholomew. The name Antarctica is the romanized version of the Greek word ἀνταρκτική (antarktiké), which means “opposite to the north”. Antarctica is not considered a country and does not belong to anyone. Although several countries have claimed parts … Read more

Many people live in Antarctica on a temporary basis, several countries have set up about 30 scientific research stations there. One of the largest is the U.S.’s McMurdo Station, where about 4,000 people live in the summer months. Most of the scientists and researchers do not spend the winter months of June, July, and August … Read more

There are plants and animals species that live in Antarctica. Those that can survive the cold, dry climate, such as mosses, lichens, and algae. Only a few small insects can live there, and then only in the coastal areas. Many more animals spend summers in the waters that surround the continent, including penguins, seals, whales, … Read more

Antarctica is about 1.5 times larger than the United States. Antarctica covers about 5.4 million square miles (14 million sq km). It’s also larger in area than either Europe or Australia. Many countries have claimed parts of Antarctica, but the nations of the world disagree about some of these claims. For example, as this map … Read more

The Norwegian explorer Roald Amundsen arrived at the South Pole in December 1911. Roald Engelbregt Gravning Amundsen was also the first person to reach the North Pole, and is also known as the first to traverse the Northwest Passage. Amundsen was a key expedition leader during the Heroic Age of Antarctic Exploration, and disappeared in … Read more

Australia was originally a British prison colony. Beginning in the late 1700s, the United Kingdom sent convicted criminals to this faraway territory. Until that time, the British had been sending convicts to their American colonies, but the American Revolution put an end to that practice. Over a period of 80 years, some 160,000 convicts were … Read more

Australia hasn’t been part of the United Kingdom since 1901, when its six colonies formed the Commonwealth of Australia. Like New Zealand, it is a member of the Commonwealth of Nations, an organization of countries that were once part of the United Kingdom. Queen Elizabeth II remains queen of Australia, even though her role is … Read more

Australia has about 22 million people, almost as many people as live in New York State. In land area, Australia is about the size of the United States minus Alaska. Most Australians, about 80 percent of them, live in the southeastern part of the country, mostly in the cities and suburbs of Sydney, Melbourne, and … Read more

It is estimated that about 22 million people live in Australia in 2010. Australia’s population has more than doubled since 1950, and most of that increase has been due to immigration. One of every five people living in Australia today was born in another country. In recent years, most people immigrating to Australia have come … Read more

Australia was home to Aborigines and Torres Strait Islanders for at least 65,000 years before Europeans settled the continent. Their plight has been similar to that of the native people in the Americas, with thousands either killed in fights with the early settlers or indirectly by the diseases the settlers introduced. Since then, the native … Read more

The huge central interior of the Australian continent is made up of desert land known as the outback. It is hot, dry, and sparsely populated. Almost in the middle of the outback is the world’s largest monolith, the famous red rock called Uluru, also known as Ayers Rock. It is 2.2 miles (3.6 km) long … Read more

Tasmania is one of its six states of Australia. Until about 12,000 years ago it was connected to Australia’s mainland. Then, rising sea waters resulting from the end of the last ice age covered the land bridge that connected Tasmania to Australia. Tasmania lies about 130 miles (209 km) south of the mainland, separated by … Read more

Often called “the long straight,” Australia’s transcontinental railroad, known as the Indian Pacific, includes the longest straight stretch of railway in the world. The straight part of the track, between Nurina and Loongana, in Western Australia, is 296 miles (477 km) long. The Indian Pacific railway is the second longest railway line in the world. … Read more

Australia became a separate continent more than 200 million years ago, plenty of time for animals to develop in a distinctively different way from animals on other continents. More than 120 species of marsupials, mammals that give birth to very immature babies who continue to develop in their mothers’ pouches, live in Australia today. These … Read more

There really is an animal called the Tasmanian Devil, and it lives in Tasmania, a large island off the southern coast of Australia. Scientists think it became extinct on the Australian mainland about 600 years ago. The Tasmanian devil is nocturnal and about the size of a small, thick-set dog. It is covered with black … Read more

The Great Barrier Reef is the largest collection of coral reefs in the world, and is the biggest single structure made by living organisms in the world. Hundreds of broken chains of coral reefs extend for about 1,250 miles (2,012 km) off the northeastern coast of Australia. The Great Barrier Reef is home to hundreds … Read more

It is estimated that about 4.4 million people live in New Zealand in 2010. Of those, about 78% identify with European ethnic groups, and most the remainder are of Māori decent. The indigenous Māori language name for New Zealand is “Aotearoa”, which means “land of the long white cloud”. Dutch explorer Abel Tasman was the … Read more

New Zealand is not really that close to Australia. New Zealand lies about 1,000 miles (1,610 km) southeast of Australia, across the Tasman Sea. Most of the country consists of two main islands, the North and the South, which together extend for about 1,000 miles (1,610 km). New Zealand’s closest neighbours to the north are … Read more

New Zealand is located in the Southern Hemisphere about halfway between the Equator and Antarctica. It sits on top of two tectonic plates, whose movement has resulted in the South Island’s magnificent mountains known as the Southern Alps. Mount Cook is the tallest of these craggy mountains, at 12,310 feet (3,753 m). In an area … Read more

Antarctica, the land that surrounds the South Pole, is even colder than the North Pole. Temperatures can reach a minimum of between −80 °C (−112 °F) and −90 °C (−130 °F) in the interior of Antarctica during winter. It rarely snows in the interior because the air is so dry due to the continent’s high … Read more