What are the Glacial Depositional Landforms

What are the Glacial Depositional Landforms

Posted by Manisha on May 27, 2020

Once our earth almost fully was covered with ice. We all know that time as the ‘Ice age’. Pleistocene Epoch is typically defined as the age of Ice, which began about 2.6 million years ago and lasted until about 11,700 years ago.

The remains of a glacier of ice age still can be seen in some areas of the world including Greenland, Alaska, and Antarctica.
But these glaciers did not just sit there and stand in one place. There was a lot of movement over time, again and again, which continue till today. These movements of glacier-formed so many new landforms.

I already discussed glacial erosional landform, which is formed due to the erosional process of a glacier.
 Now, here in this post, I am going to discuss the landforms which are formed by the depositional process of the glacier, known as a glacial depositional landform

Glacial Depositional Landform

1. Moraines

It is an important depositional feature or landform of Glacier.
It is formed when glacier starts melting and starts leaving and depositing its all carried debris on its way. Basically moraines are formed from debris previously carried along with a glacier, consists of loose sediments and rock debris and deposited on the surface, these materials also known as till.

Till may consist of rounded particles ranging in size from minute sand particles or glacial flour to large boulders (15-20 meter large).

Moraines can be classified into five types. These are : 

  1. Lateral Moraines: These are parallel ridges of debris deposited along the sides of a glacier. These are usually preserved as high ridges.

  2. Medial Moraines: It is a ridge of Moraine that runs down the center of a valley floor, formed when two glaciers meet and the debris on the edges of the adjacent valley sides join and are carried on top of the enlarged glacier. As the glacier melts, the debris deposited and a ridge is created down the middle of the valley floor.

    For example, Kluane National Park, Yukon has a Medial Moraine of 1 kilometer wide.

  3. Terminal Moraines: It is also known as End Moraines.
    These are the ridges of unconsolidated debris deposited at the end of the glacier.

  4. Recessional Moraine: These are often observed as a series of transverse ridges running across a valley behind a terminal moraine. They are formed perpendicular to the lateral moraine, created during the temporary halts in a glacier’s retreat.

  5. Ground Moraine: It is till covered areas with no ridges and regular topography like plains. These are accumulated at the base of the Ice as lodgement till.
2. Drumlin

It is an oval-shaped hill or an elongated hill of inverted spoon-shaped depositional glacial landform, which is formed by glacial ice action on underlying unconsolidated till or ground moraine.
Clusters of drumlin create a landscape that often looks like a half-buried egg that is why it also named Basket of Eggs Topography.

For Example, commonly found in North Ireland, USA, and Finland.

3. Eskers

These are long narrow, widening (to the role) or mound of sand, gravel, and boulders deposited by subglacial meltwater stream.
The height of these Esker varies from 5-50 meter and length from 20-25 kilometers and more.
These look like a natural embankment.

For example, found in the U.S.A., Canada, Ireland, Sweden.

4. Kame

It is an irregular mound-shaped hill which is composed of till gravel, and sand that can be observed after the retreat of the glacier. It formed a delta-like landform of the glacier.

5. Kettle Hole

It is a depression or hole in an outwash plain formed by retreating glacier or draining floodwater.
These are formed as a result of blocks of dead ice left behind by retreating glaciers, which later surrounded by sediments, deposited by meltwater streams of the glacier.

For example, found in Preyries of U.S.A., North America.

6. Outwash Plain

It is also named as Sandur.
It looks like plains of glacier found at the front of the glacier and where material like sediments are deposited over a wide area, carried by glacier meltwater.

So, these are some glacial depositional landform which is formed due to the depositional process of glaciers, over a long period of time.
This way glaciers also contribute themselves in shaping the Earth's crust, as we seeing it today.
 
I saw glaciers only in videos and photos but not so lucky to feel and saw its mesmerizing beauty in reality, except seeing snowfall and snow, which found only in the winter season.
If you are lucky enough and visited or had any beautiful encounter with these landforms than share here, to inspire us. Write to me about what you like the most about it and why. Also write what is that thing or inspiration, which takes you into the lap of these glaciers?