Lava cave

A lava cave is any cave formed in volcanic rock. These special caves are usually made by volcanic processes, which are called volcanic caves. While other types of caves, like sea caves, can also be found in volcanic rock, they are formed by different processes and often long after the rock was created. Lava caves are fascinating because they show us how volcanoes shape the Earth and give us a glimpse into the powerful forces deep within our planet. Exploring these caves helps scientists learn more about Earth's history and the amazing work of nature.

Types

Lava tubes

Main article: Lava tube

Lava tubes are the most common type of lava cave. They usually form in smooth, slow-moving lava flows. As the lava flows, the outer parts harden while the inside continues to move, creating tunnels. These tunnels help keep the lava hot and allow it to flow farther. Depending on the slope, terrain, and how thick the lava is, different kinds of lava tubes can form, such as those that branch out or stack on top of each other.

Surface tube

Surface tubes are small channels formed by fast-moving lava on hardened surfaces. They are usually too small to enter and help lava tubes grow longer. These tubes are often buried but can sometimes connect to larger lava tubes below the surface.

Inflationary caves

Inflationary caves are small chambers that form when pressurized lava pushes rock aside. After the lava drains away, these chambers remain. They can sometimes be mistaken for lava tubes because they look similar. An example can be found in pressure ridges, which are hardened lava formations that may have hollow spaces inside.

Liftup caves

Liftup caves form near pressure ridges or flat areas of hardened lava. As the edges expand outward, they can leave small spaces underneath. These caves are usually short but can sometimes be longer.

Open vertical conduits

Main article: Pit crater

Open vertical conduits are deep, round or oval-shaped passages that lava used to travel through to reach the surface. They can be very deep and wide, with walls that have small hanging points of rock. Some of the deepest known examples are found in Iceland.

Pit craters

Pit craters form when magma almost reaches the surface but then drains away, leaving a large hole. These craters can have very steep walls and sometimes connect to hidden spaces below the surface. In Hawaii, some pit craters lead to deep vertical passages.

Rift caves

Rift caves form along cracks in volcanic rock, often where lava flows or erupts. These caves can be very deep and are sometimes filled with spilled lava. One well-known example is Crystal Ice Cave in Idaho, part of Craters of the Moon National Monument and Preserve.

Lava mold caves

Lava mold caves form when lava flows around objects like trees or animals. After the objects burn away or decay, they leave hollow spaces shaped like what they once were. These caves can be found in places like Washington state and Japan.