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Lava field

earth science Maturity 7-9 Next article →

A lava field is a very large area of land covered by lava flows.

Hells Half Acre
Hells Half Acre

These areas are sometimes called lava beds. Most lava fields consist of highly fluid basalt lava. This type of lava flows easily across the ground. Because the lava is so liquid, fields can be massive. They can stretch for tens or hundreds of kilometers across a landscape. These features change the shape and texture of the underlying terrain.

The way a lava field looks is called its morphology. Scientists study this shape to understand how the lava moved. The ridges and patterns on the surface reveal much information. They show the direction that the lava channels traveled. These patterns can also show active lava tubes. These are hollow tunnels that may exist underneath the solidified crust. The surface can also tell us if the lava was pāhoehoe or 'a'ā.

Iceland (3), Reykjanes peninsula
Iceland (3), Reykjanes peninsula

There are two main structures for lava fields. The first type is called sheet flow lava. This lava appears like a wrinkled or folded sheet. The second type is called pillow lava. This lava is bulbous in shape. It often looks like a pile of pillows stacked on top of one another.

Bárðarbunga Volcano, September 4 2014 - 15123275226
Bárðarbunga Volcano, September 4 2014 - 15123275226

The specific structure depends on how the lava behaves as it cools.

One interesting process is known as lava flow inflation. This happens specifically in pāhoehoe flows with a high effusion rate. The effusion rate is how much lava flows out over time. First, a thin crust forms on top of the liquid lava. However, the fluid lava continues to flow underneath this crust. Because the flow rate remains high, the entire structure increases in size. This inflation can make the field grow up to four meters in height. This process helps scientists learn about the physics of lava.

Geography also plays a role in how these fields form. Some lava fields are subaqueous, which means they form under water. The location of the volcano changes the lava's shape. For example, sheet flow lava is found near fast-flowing volcanic centers. The Galapagos Rift is one such location. In contrast, pillow lava is found near slow-flowing centers. The Mid-Atlantic Ridge is a place where these pillow structures form.

Many notable lava fields exist around the world. The Boring Lava Field is located in the United States. In Idaho, there is the Hell's Half Acre Lava Field. In Saudi Arabia, the Harrat Rahat field threatened Medina in the 13th century. Iceland is also home to many fields. The Reykjanes peninsula is described as a barren waste of lava fields. The Ögmundarhraun fields in Iceland were created by an eruption in 1151 AD. In Utah, the city of St. George is built around lava rocks and bluffs.

Scientists use different methods to map these dark areas. Most large fields are studied from the air or via satellite photos. This is because the lava is a dark, near-black color. This color creates a sharp contrast against the rest of the landscape. Researchers use computer models to try and predict where new fields will appear. However, current models struggle to be perfectly accurate. This is because many small, random factors influence the flow. These include the source geometry and the specific lava extrusion rate.

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🖼️ Images & Media (4)
File:Hells Half Acre.jpg
Hells Half Acre.jpg
File:Iceland (3), Reykjanes peninsula.JPG
Iceland (3), Reykjanes peninsula.JPG
File:Bárðarbunga Volcano, September 4 2014 - 15123275226.jpg
Bárðarbunga Volcano, September 4 2014 -...
File:View of Ögmundarhraun lava field in Iceland from Road 427.jpg
View of Ögmundarhraun lava field in...
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