Natural Processes That Shape The Earth by Lesley Degamo

Alpine Glaciers

denicecelis — 2024-12-06 03:27:18 UTC

Alpine glaciers, also known as mountain glaciers, are masses of ice that form on the slopes of mountains. These glaciers exist due to the accumulation of snow that compresses into ice over time. Alpine glaciers move slowly down mountains, carving out valleys and shaping the landscape. They are crucial for supplying water to rivers, especially in regions that depend on meltwater. Some notable locations include the Himalayas, Rockies, Andes, Alps, and the Southern Alps of New Zealand. These glaciers are typically narrow and confined to the topographical features of mountain ranges.

How are glaciers formed?

denicecelis — 2024-12-06 03:28:03 UTC

Alpine glaciers, also called mountain glaciers, form when a lot of snow piles up in the mountains. Over many years, the snow becomes packed tightly and turns into ice. This is called accumulation. The ice then starts to move down the mountain like a slow river. As the glacier moves, it picks up rocks and dirt from the ground. This is called plucking. These rocks and dirt help the glacier scrape and wear away the land underneath. This process is called erosion. The glacier shapes the land into unique features like U-shaped valleys, which look like wide, curved valleys, and cirques, which are bowl-shaped areas carved into the mountains.

When the glacier melts, it drops all the rocks and dirt it was carrying. This process is called deposition. Deposition happens when the materials picked up and carried by the glacier are laid down in a new location. Over a long time, these glaciers shape the mountains and valleys, creating beautiful landscapes.

How are alpine glaciers changing?

denicecelis — 2024-12-06 03:28:17 UTC

Alpine glaciers, found in mountains, are shrinking quickly because of rising temperatures caused by human activities such as burning fossil fuels, cutting down forests, and producing waste. These activities release greenhouse gases that trap heat and warm the Earth, causing glaciers to melt faster than ever before. This melting affects plants, animals, and people who rely on glacier water. As glaciers melt and move back, they leave behind lakes that can sometimes flood nearby areas.

Reference/s:https://education.nationalgeographic.org/resource/glacier-moving-rivers-ice/, https://education.nationalgeographic.org/resource/erosion/

Hawaii Islands

denicecelis — 2024-12-06 03:29:08 UTC

Hawaii is a group of volcanic islands in the central Pacific Ocean. The six biggest Hawaiian Islands—Hawaii (the Big Island), Maui, Lanai, Molokai, Oahu, and Kauai—are lined up because of how they were made. A big piece of the Earth's crust called the Pacific Plate moves over a hot spot (a very hot area deep inside the Earth where magma, which is melted rock, rises to the surface). This hot spot is like a big fountain of hot, melted rock from deep inside the Earth. As the Pacific Plate moves over this hot spot, the hot rock breaks through the Earth's crust and makes islands one after another. That’s why the islands are in a line.

The Dead Sea

lezley1 — 2024-12-06 03:29:13 UTC

The Dead Sea is a salt lake. It is located in southwestern Asia between Jordan on the east and Israel and the West Bank on the west. The Dead Sea has so much salt in it that only microbes (microscopic organisms) can live in it. Its salt content is about seven times that of the ocean. The land surrounding the Dead Sea is a desert. The hot summer temperatures cause the lake’s water to evaporate at a high rate. When the water evaporates it leaves behind salt. The area gets very little rain so the water that evaporates is not replaced very quickly. Because of that, a high concentration of salt has built up in the Dead Sea over the years.

How Do Volcanoes Form?

denicecelis — 2024-12-06 03:29:32 UTC

The rock cycle is essential in forming volcanoes. Deep inside the Earth, intense heat and pressure cause rocks in the mantle to melt, creating magma. This magma, being less dense than the surrounding solid rock, rises through cracks and weak points in the Earth's crust. When the magma reaches the surface, it erupts as lava, resulting in a volcanic eruption. The lava then cools and solidifies, forming igneous rocks. Over time, repeated eruptions add more layers of lava and ash, building up the structure of a volcano. Each eruption contributes to the growth and development of the volcano by adding new layers that cool and harden. Thus, the rock cycle links the processes of melting, rising, and solidifying to form and sustain volcanoes on the Earth's surface.

How have the Hawaiian islands changed over time?

denicecelis — 2024-12-06 03:29:44 UTC

The Hawaiian Islands were formed by volcanoes. A long time ago, hot molten rock called lava came out of the ground and cooled down to make the islands. This process is still happening today! Over many years, wind, rain, and waves have worn down the islands, this is called erosion. It shapes the mountains and creates beautiful beaches. When the islands first formed, there were no plants or animals. Over time, plants started to grow, and animals came to live on the islands. Some of these plants and animals are found only in Hawaii!

References: https://education.nationalgeographic.org/resource/chain-islands-hawaiian-hot-spot/, https://www.gsi.ie/en-ie/education/rocks-minerals-and-gems/Pages/The-rock-cycle.aspx

Mariana Trench

denicecelis — 2024-12-06 03:30:28 UTC

The Mariana Trench is a deep-sea trench (a deep and narrow hole, or ditch, in the ground) in the floor of the western North Pacific Ocean. It's a deep narrow valley located underwater, located about 124 miles (200 kilometers) east of the Mariana Islands. It is the deepest such trench known on Earth and thus the deepest known point in the ocean. More than 35,000 feet (10,500 meters) deep at its deepest point, the Mariana Trench is far lower than the lowest point on land, the Dead Sea. The trench is deeper than how high Mount Everest is.

What is Subduction?

denicecelis — 2024-12-06 03:30:57 UTC

The Mariana Trench was formed by subduction. Think of the Earth's surface like a giant jigsaw puzzle made of huge pieces called plates. These plates sometimes move and collide. During subduction, the larger Pacific Plate gets pushed under the smaller Mariana Plate. As the Pacific Plate goes under, it bends and sinks deep into the Earth, forming a deep trench. Subduction has created much of the Earth's continental crust.

Volcanoes can play a part too!

denicecelis — 2024-12-06 03:31:16 UTC

When that plate slides under, it melts and creates magma, which is super hot, melted rock. Sometimes this magma finds a way to the surface and erupts as a volcano. While the Mariana Trench itself isn't from volcanic eruptions, the same moving plates that form the trench can also cause volcanic activity nearby.

How The Dead Sea was Formed

lezley1 — 2024-12-06 03:31:18 UTC

Imagine two big puzzle pieces drifting apart—that’s how the Great African Rift Valley began! About 25 million years ago, the African Plate and the Arabian Plate started moving away from each other. This created a huge split called the Great African Rift Valley.

As time went on, from about 23 million to 5 million years ago, the Arabian Plate and the Eurasian Plate started to slide past each other. This movement created another valley called the Jordan Rift Valley. The Dead Sea sits in this Jordan Rift Valley.

Rivers flow into the Dead Sea, bringing in lots of minerals and salts. The hot climate causes water from the Dead Sea to evaporate quickly. As water evaporates, it leaves the salts and minerals behind, increasing the salinity of the water that's left.

For a long time, up until the 1970s, this made the lake have two different layers of water.

Top Layer (up to 130 feet deep):
- Temperature: Between 66 to 98 °F (19 to 37 °C).
- Salty, but not the saltiest (about 300 parts per thousand).
- Rich in other minerals like sulfates and bicarbonates.
Bottom Layer (130 to 330 feet deep):
- Temperature: Always around 72 °F (22 °C).
- Extra salty (about 332 parts per thousand).
- Full of different minerals like magnesium, potassium, chlorine, and bromine.
- Has hydrogen sulfide, a stinky gas that smells like rotten eggs.

At the bottom, the water is super salty and dense, so it doesn't mix with the top layers. This water stays there for a very long time, becoming what we call "fossilized water."

How is the Mariana Trench shaped over time?

denicecelis — 2024-12-06 03:31:28 UTC

The Mariana Trench’s shape is influenced by the movement of Earth's giant puzzle pieces, called tectonic plates. Over time, one of these pieces, the Pacific Plate, has been sliding under another one. This sliding action has made the trench slowly move eastward like it's rolling back.

So, think of it like a giant piece of the Earth moving and rolling back over a long time, which makes the trench move to the east bit by bit.

Reference/s: https://oceanexplorer.noaa.gov/okeanos/explorations s, www.britannicakids.com, www.geographic.co.uk

How is the Dead Sea shaped over time?

lezley1 — 2024-12-06 03:32:20 UTC

Over the past 10,000 years, the water in the Dead Sea has been evaporating faster than it gets refilled by rain. As the water levels go down, the Dead Sea becomes even saltier. When the water level drops, it causes big holes called sinkholes to form around the shore. People still visit the Dead Sea because it's famous for helping with health problems and for the fun floating experience.

But the changes in water levels have affected tourism. There are plans to help the Dead Sea,

like bringing water from the Red Sea to help stop

it is shrinking.

Reference/s: https://kids.britannica.com/students/article/plate-tectonics, https://education.nationalgeographic.org/resource/process-evaporation/

Sahara Desert

lezley1 — 2024-12-06 03:33:25 UTC

The Sahara is the largest hot desert on Earth and the hottest region in the world during summer days, with temperatures often exceeding 120 °F (49 °C). At night, the air cools significantly. Rain is extremely rare, but when it does occur, it usually comes in powerful storms. Most of the Sahara's surface is rocky, featuring flat plains, plateaus, and some mountains. Sand covers about one-quarter of the desert, forming high dunes in certain areas.

How the Sahara Desert was formed

lezley1 — 2024-12-06 03:33:59 UTC

The Sahara Desert was shaped by tectonic activity, particularly through the movements of the African Plate. Over millions of years, this plate has moved and changed the land a lot. When the plate moved, it pushed up mountains like the Atlas Mountains and the Ahaggar Mountains. The Atlas Mountains stretch across the northwest corner of Africa, providing a natural barrier between the Mediterranean coast and the Sahara Desert.

The movement of the African Plate also caused volcanic activity, leaving behind volcanic rock formations in some parts of the desert. In addition to creating mountains, the plate movement stretched and thinned the Earth's crust in some places. This stretching formed rift valleys, which are long, narrow depressions, and created basins and low areas that are typical in deserts. These basins often become the sites of temporary lakes that fill up with water after rainfall and then dry up.

The Sahara Desert is also shaped by wind erosion. These winds pick up and move sand, forming big sand dunes that can be as tall as buildings. Dunes are hills of sand shaped by the wind and they constantly change shape. The wind also removes small particles, leaving behind bigger rocks and pebbles. This process is called deflation. The wind-blown sand acts like a natural sandblaster, wearing down rock surfaces.

How is the Sahara Desert shaped over time?

lezley1 — 2024-12-06 03:36:00 UTC

Over thousands of years, erosion has created unique shapes in the desert, like yardangs (streamlined ridges formed by wind erosion) and inselbergs (isolated hills or mountains that rise suddenly from a flat plain). These features make the Sahara Desert look very special.

Reference/s: https://kids.britannica.com/students/article/plate-tectonics, https://www.britannica.com/science/sand-dune/Winds