Rift valley

The ground can pull apart.

This makes a long, low land. It looks like a deep crack. This is a rift valley.

Water can fill these cracks. This makes big lakes. Some lakes are very deep. One lake is in Siberia. It is the deepest lake on Earth. These valleys can even be on Mars. They can be on moons, too. The world has many amazing cracks.

A rift valley is a long, low area of land. It sits between high lands or mountains.

Rifts form when the lithosphere pulls apart. The lithosphere is the outer layer of our Earth. As the ground pulls, the land sinks. This creates a deep crack. Over time, wind and water can make it deeper. This is called erosion.

Many big lakes live in rift valleys.

Lake Baikal in Siberia is in an active rift. It is the deepest lake on Earth. It holds 20% of all liquid fresh water on our planet. Lake Tanganyika is also in a rift. It is the second deepest lake.

Rifts are not just on Earth. We see them in space, too. Mars has a huge rift system. It is 4,000 km long. It is called Valles Marineris. Moons like Titania and Charon also have rifts. These rifts show how different worlds change over time.

A rift valley is a long, low area of land. It sits between high lands or mountain ranges. These valleys form because of a geologic rift. This happens when the lithosphere pulls apart. The lithosphere is the outer layer of our Earth. As the ground stretches, the land sinks down. This creates a long, linear depression.

Over time, wind and water can make the valley deeper. This is called erosion. These valleys often fill up with sediment. Sediment is material that washes down from the sides. Many rift valleys also hold huge lakes.

How these valleys work can be quite complex. Sometimes, tectonic plates are actually breaking apart. This process can turn a continent into an ocean. Other rifts come from bends in faults. A fault is a crack in the Earth's crust. If a fault has a bend, the ground might stretch. This stretching causes the land to sink. This is called subsidence. Small rifts can even make sag ponds. These are small pools of water. Larger rifts can change the whole shape of a landmass.

Scientists study many different types of rifts. The most extensive rift is on the sea floor. It follows the mid-ocean ridge system. This happens because of sea floor spreading. The Mid-Atlantic Ridge is a famous example. The East Pacific Rise is another one. On land, some rifts are still active today. The East African Rift is very well known. The Rio Grande rift is also active. The Baikal Rift Zone is a third active one.

There is also a fourth one in West Antarctica.

Many of the world's largest lakes live in rifts. Lake Baikal in Siberia is a World Heritage Site. It is the deepest lake on Earth. It holds 20% of all liquid freshwater on Earth. Lake Tanganyika is also very deep. It sits in the Albertine Rift. This is part of the East African Rift.

In North America, Lake Superior is very large. It sits in the ancient Midcontinent Rift. Other lakes like Lake Vostok might be in old rifts. Even in Canada, the Ottawa-Bonnechere Graben holds lakes.

We can find rift valleys in space, too. Mars has a giant system called Valles Marineris. It is 4,000 km long. On Venus, the Devana Chasma is 4,000 km long. Some moons also have these huge cracks. Tethys has the Ithaca Chasma, which is 2,000 km long. Charon has the Nostromo Chasma. Even the moon has ancient rift valleys. These include Vallis Rheita and Vallis Alpes. Looking at these rifts helps us understand other worlds.

A rift valley is a long, low area of land. It sits between higher lands or mountain ranges. These valleys are created by a geologic rift. This happens because of extensional tectonics. This term describes the pulling apart of the lithosphere. The lithosphere is the outer layer of the Earth. As the ground stretches, the land sinks down. This creates a linear depression.

Over time, forces of erosion can make these valleys even deeper. The valleys often fill with sedimentary deposits. These deposits come from the rift flanks and surrounding areas.

The process of forming a rift can happen in many ways. One method involves the breaking apart of entire tectonic plates. When this happens, the crust pulls away from itself. If this process continues, a continental rift can eventually become an oceanic rift. Another way rifts form is through faults. A fault is a crack in the Earth's crust. Some rifts happen because of bends in strike-slip faults. These are faults where rocks move horizontally past each other. If a bend occurs in the direction of the motion, extension happens. This stretching causes subsidence, which is the sinking of the ground.

Geologists categorize rifts into several different types. The most extensive rifts are found on the sea floor. These occur along the crest of the mid-ocean ridge system. This is caused by a process called sea floor spreading. Examples include the Mid-Atlantic Ridge and the East Pacific Rise. Other rifts are continental in nature. Some are the result of a failed arm of a triple junction. These failed arms are called aulacogens. On a smaller scale, faults can create minor features. These include things like landslides or small sag ponds.

Several continental rift valleys are currently active on Earth. The East African Rift is one of the most famous examples. The Rio Grande rift is another active system. The Baikal Rift Zone is a third active continental rift. Scientists also believe the West Antarctic Rift System may be active. These active rifts show how the Earth's surface is still changing. They provide a way to study how plates move and break. These systems can eventually change the map of our entire planet.

Rift valleys are often home to some of the largest lakes on Earth. Lake Baikal in Siberia is a famous example. It is a World Heritage Site located in an active rift valley. Baikal is the deepest lake in the world. It also holds the greatest volume of liquid freshwater on Earth. It contains 20% of all the liquid freshwater on our planet.

Lake Tanganyika is the second largest by both depth and volume. It sits in the Albertine Rift in East Africa.

Other significant lakes are also tied to rift systems. Lake Superior in North America is the largest freshwater lake by area. It lies within the ancient and dormant Midcontinent Rift. In Canada, the Ottawa-Bonnechere Graben contains Lake Nipissing and Lake Timiskaming. Some scientists believe the subglacial Lake Vostok may also lie in an ancient rift valley. These lakes show how much water can collect in these low areas. They demonstrate the long-lasting impact of geologic rifts on the landscape.

Rift valleys are not unique to Earth. We can find them on other planets and moons in our solar system. Mars has a massive rift system called Valles Marineris. This system is 4,000 km long. On Venus, the Devana Chasma is also 4,000 km long. Some natural satellites also show these features. The moon Tethys has the Ithaca Chasma, which is 2,000 km long. Charon has the Nostromo Chasma in the Pluto system.

Studying these rifts helps us understand the geology of the entire solar system.