For decades, scientists have wondered why there are so many volcanoes in the northernmost regions of North America. Normally, volcanoes occur when one or more continental plates separate or collide.

In the northern regions of Canada and Alaska, there are many volcanoes compared to other regions. In Alaska alone, there are more than 40 active volcanoes.

Now means two researchers from Houston in the United States have solved the puzzle.

Faded away

Scientists believe that at one time there was a third seabed slab in the area, but it disappeared under the Earth’s crust 40 to 60 million years ago.

– The plates of the ocean fall back into the Earth’s mantle as they cool. Plates on earth don’t, says John Hopper, a professor at the National Geological Surveys of Denmark and Greenland DR.

When the oceanic plate collides with a continental plate, the heavier oceanic plate will be pushed under the lighter continental plate. Over time, the plate from the bottom of the ocean will penetrate inside the Earth.

– Very interesting

Researchers had to sift through thousands of sound wave measurements in the earth and calculate them to establish that there was an undersea plate beneath Canada and Alaska millions of years ago. They are also said to have pieced together what the tectonic plates looked like in the Pacific at the time.

According to the website technology explorer there have long been doubts about the missing ocean floor plate theory.

Professor Hopper thinks the study is exciting.

– It’s very interesting that they were able to demonstrate that the disc was actually there once. Their method can make us wiser when it comes to this tectonic plates he said to DR.