Why is Greenland considered an island while Australia is a continent?
Australia is three and a half times larger than Greenland and comprises most of the land on the Indo-Australian Plate, while Greenland is distinctly part of the North American Plate.
What is an archipelago?
An archipelago is a chain (or group) of islands that are close to one another. The Aleutian Islands of Alaska and the Hawaiian Islands are both archipelagos. They are usually formed by plates pushing into one another or by volcanic activity.
Atolls like these in the Maldives are formed of coral reefs surrounding what was once a volcano.
What is a coral reef?
Coral reefs are formed by the accumulation of calcium carbonate that comes from the external skeletons of tiny animals called coral polyps. The polyps live in shallow, warm water and thus congregate around islands in the tropics, where coral reefs are abundant.
What is an atoll?
In addition to reefs, coral can also form atolls. Atolls are formed when a volcano, around which coral often grows, erodes away, leaving a circular wall of coral with a lagoon at the center.
What is a strait?
A strait is a narrow body of water between islands or continents that connects two larger bodies of water. Two of the most famous straits are the Strait of Gibraltar, which connects the Mediterranean Sea and the Atlantic Ocean, and the Strait of Hormuz, which connects the Persian Gulf to the Gulf of Oman.
HIGH, LOW, BIG, SMALL, AND WONDROUS
Where is the lowest point on Earth?
To reach the lowest point on Earth, you would have to go far below the Pacific Ocean, south of Guam to the Marianas Trench, at a place known as Challenger Deep. Its maximum known depth is 6.831 miles or 36,070 feet (10,994 meters).
Is the lowest point on Earth actually closer to the center of the Earth?
No, because of the Earth’s irregular shape—it is not a perfect sphere—places in the Arctic Ocean are technically closer to the Earth’s center than the Mariana Trench, although not as deep.
Where is the world’s lowest point on dry land?
The world’s lowest point is at the shore of the Dead Sea on the border of Palestine, Israel, and Jordan. It is 1,378 feet (420 meters) below sea level.
What are the lowest points on each continent?
In Africa, the lowest point is Lake Assal in Djibouti, 509 feet (155 meters) below sea level. In North America, California’s Death Valley lies at 282 feet (86 meters) below sea level. Argentina’s Laguna del Carbón is the lowest point in South America at 345 feet (105 meters) below sea level. The Caspian Sea in Europe lies at 92 feet (28 meters) below sea level. In Asia the shoreline of the Dead Sea lies at 1,378 feet (420 meters) below sea level. And Australia’s lowest point is a mere 52 feet (16 meters) below sea level at Lake Eyre.
How does the hydrologic cycle work?
The movement of water from the atmosphere to the land, rivers, oceans, and plants and then back into the atmosphere is known as the hydrologic cycle. We can pick an arbitrary point in the cycle to begin our examination. Water in the atmosphere forms clouds or fog and falls (precipitates) to the ground. Water then flows into the ground to nourish plants or into streams that lead to rivers and then to oceans, or it can flow into the groundwater (underground sources of water). Over time, water sitting in puddles, rivers, and oceans evaporates into the atmosphere. Water in plants is transpired into the atmosphere.
What is evapotranspiration?
The process of water moving into the atmosphere is collectively known as evapotranspiration. It is the combination of water vapor being evaporated from the surface of the Earth (such as from lakes, rivers, or puddles) into the atmosphere, and transpiration, which is the movement of water from plants to the air.
Where is all the water?
Over 97% of the world’s water is contained within oceans and is too salty to drink or to irrigate crops with (except when the water is cleaned through a desalination plant, which is not done very often). About 2.8% of the world’s water supply is fresh water. Of that 2.8%, about 2% is frozen in glaciers and ice sheets. This leaves only about 0.8% of the world’s water that is accessible through aquifers, streams, lakes, and in the atmosphere. The water that we use primarily comes from this 0.8%.
How many people in the world have limited access to clean water?
According to experts at MIT, approximately 700 million people have limited access to clean water. This number will swell to approximately 1.8 billion people over the next ten years as the global population grows and demand for industrial water used for manufacturing, power generation, agriculture, and energy production continues to accelerate.
What is desalination?
Desalination is the process of removing some salt and minerals from ocean water in order to produce consumable fresh water for a population. According to experts at the International Desalination Association, there are approximately 17,000 desalination plants worldwide in 150 countries, producing 21.1 billion gallons (66.5 cubic meters) per day. Three hundred million people in the world rely on desalinated water for their daily drink water needs. Twenty percent of all water used in Israel is desalinated water that comes from the Mediterranean Sea. It is estimated that by 2016, 50% of Israel’s water supply will be produced in the country’s desalination plants.
Desalination plants remove salt from seawater to create fresh drinking water. The process has improved over the years, but there is still the problem of what to do with all the salt and other minerals that are generated from the process.
What is a desalination plant?
A desalination plant is a facility that pumps ordinary seawater through a myriad of expensive equipment and processes, transforming the salty water into fresh water. This process has been used with some success in many parts of the world, including the United States, the Caribbean, and the Middle East. It is much more efficient and less expensive, however, to clean wastewater (water that has been used for bathing, cooking, cleaning, etc.) than it is to clean and desalinate seawater.
How many desalination plants are there?
There are approximately 17,000 plants located throughout the world. Saudi Arabia alone accounts for 24% of the world output of fresh water from desalination. More than half of the world’s desalination plants are located in the Middle East due to the need for fresh water for the petroleum industry. The United States accounts for another 15% of all plants, Europe and Asia 10% each, and Africa approximately 6%.
Where is the biggest desalination plant in the United States?
The biggest desalination plant is in Carlsbad, California, where it opened in December 2015 at a cost of approximately $1 billion. It is capable of producing 50 million gallons (188 million liters) of drinking water to arid San Diego County per day. This is a fraction of the largest plant in the world, the Jebel Ali Plant in the United Arab Emirates, which produces over 140 million