Volcanoes are points in the earth’s crust that allow for the release of magma, gasses, and ash. Stuff from below the earth’s surface comes to the top when they erupt. When it gets to the top, it comes out in such a way that a volcano is formed because lava stacks up on itself. An extinct volcano is one that no longer has access to a lava supply. This differs from dormant volcanoes that still can erupt at any given moment. Scientists have a hard time telling the difference between dormant and extinct volcanoes for a variety of reasons but there are a few rules of thumb. Volcanoes that haven’t erupted in the last 10,000 years are often considered extinct. Every mountain on the planet is not a volcano. Which mountains are extinct volcanoes? We’ll look at 8 of them now.
8 Extinct Volcanoes
These are 8 of the extinct volcanoes on earth:
1. Calupin Volcano in New Mexico
This extinct volcano last erupted about 60,000 years ago and it isn’t expected to erupt again. In New Mexico at the time of this volcano’s formation, there was a lot of lava, ash, and volcanic activity occurring. Calupin volcano is responsible for spreading 15 square miles of lava over the landscape when it was alive. Calupin volcano is the remnants of a cinder cone volcano. Cinder cone volcanoes are the easiest volcano to form and the most recognizable. When magma is ejected and lava rains down, it falls around the blast hole forming the characteristic cinder cone. It is part of an 8,000 square mile volcanic field. This volcanic field is called the Raton-Clayton Volcanic Field. A volcanic field is the area of the earth’s crust that is or was an active source of volcanic activity.
2. Ben Nevis in the UK
This is the tallest mountain in the United Kingdom, the British Isles, and Scotland. The peak shows that this is an ancient volcano with a collapsed dome. Collapsed domes happen when the roof of a volcano falls into the magma chamber fueling the volcano from underneath. This volcano faced its extinction 350 million years ago. Ben Nevis collapsed in on itself which created a huge explosion. Evidence of this explosion is found in the rocks on and near the mountain.
3. Mount Thielsen in Oregon
This extinct volcano last erupted around 250,000 years ago. It’s a shield volcano which means that the lava that it spewed was runnier than that used to form cinder cone volcanoes. This means the lava spread out over a greater distance before cooling which creates sides with a very gradual slope. They’re called shielf volcanoes because they look like a warrior’s shield lying on the ground. Glaciers during the last ice age then rubbed up against Mount Thielsen eroding a sizeable portion of it. This is why its peak is spindly and horn-shaped.
4. Waw an Namus in Lybia
There are several lakes in the area around Waw an Namus, which attract large populations of mosquitos. Waw an Namus translates to “oasis of mosquitos.” This extinct volcano is most likely around 200,000 years old though some think it’s substantially younger. It’s a caldera that rises out of the desert. It’s surrounded by black tephra. Tephra is a fragmental material made from any pyroclastic activity. It’s different from a pyroclastic flow because it is in bits and pieces instead of it forming into one continuous rock.
5. Tamu Massif in the Pacific Ocean
Tamu Massif is an extinct volcano underwater in the Pacific Ocean. It’s the remnants of a shield volcano and its slopes are gradual at no more than 1 degree on average. It’s part of an underwater mountain range that was formed by volcanic activity called the Shatsky Rise. This volcano burned fast and brightly before it went extinct. It was formed about 145 million years ago and went extinct just a few million years later. It’s currently cut off from magma by more than 19 miles of the earth’s crust so it’s believed it’ll never erupt again. Some like to think it’s one of the largest shield volcanoes in the solar system, but that isn’t necessarily true as it may have been formed with the help of tectonic plates. If it wasn’t created in one single eruption, it’s not a pure shield volcano.
6. Mount Slemish in Ireland
This is just one of several extinct volcanoes in Ireland. This volcano and all of the others haven’t erupted in over 60 million years. Mount Slemish is the remnants of a plug of a much larger volcano. The remaining rock that had surrounded the plug has eroded over time. The plug we see now was formed right before Mount Slemish went extinct.
7. Ciomadul Volcano in Romania
The crater of this volcano is filled with water which creates Saint Anne Lake. The last eruption was around 30,000 years ago but scientists recently discovered that the volcano still has an active magma source. That doesn’t mean the volcano is going to erupt any time soon or at all. However, it does bring to light that our understanding of volcanoes and volcanic activity is still developing.
8. Sutter Buttes in California
The Sutter Buttes consist of a few lava domes that have eroded since the corresponding volcanoes were active around 1.6 million years ago. They’re associated with the same activity that created the Coastal Range in California. These buttes represent the only lava flow that’s occurred in the Central Valley of California.
