Cardiff University scientists have revealed the depth and magnitude of the internal ‘plumbing system’ that drives volcanic activity around the world.
Their study of pockets of magma contained within crystals has revealed that the large chambers of molten rock which feed volcanoes can extend to over 16 km beneath the Earth’s surface. Previous estimates suggested that magma chambers were located up to 6 km below the surface.
Interconnected magma chambers and reservoirs are the main driver of volcanic systems around the world. Mid-ocean ridges make up the most significant volcanic system on our planet, forming a roughly 80,000 km long network of undersea mountains along which 75 percent of Earth’s volcanism occurs. Because of their depth, their study is difficult.
It is known that magma plumbing systems exist below the Earth’s surface, which can be thought of as a series of interconnected magma conduits and reservoirs, similar to the pipes and tanks that make up plumbing systems in a house.
Lead author of the study, Emma Bennett, said: ‘To calculate the depths of magma reservoirs we used melt inclusions, which are small pockets of magma that become trapped within growing crystals at different depths in the magmatic system. These pockets of melt contain dissolved CO2 and H2O.
The results of the study showed that magma plumbing systems at mid-ocean ridges extend to much greater depths than previously thought. Oceanic crust is normally only around 6 km thick, and previously magma chambers were thought to be located there. The new data shows that the plumbing system extends to at least 16 km depth.
https://phys.org/news/2019-08-scientists-uncover-deep-rooted-plumbing-beneath.html