An international team of scientists studying volcanoes in the Galapagos Islands in the Pacific Ocean off the coast of Ecuador has discovered that the volcanoes that produce small basaltic lava at their eruptions actually conceal a chemically diverse magma in its underground core. Some of these volcanoes also have the ability to cause explosive activity.
Safe and rebellious volcanoes
Most volcanoes have erupted similarly millions of years ago. For example, the volcanoes of Iceland, Hawaii and the Galapagos Islands are constantly erupting, producing lava flows. These volcanic lava is made of molten basalt rocks, which soon formed long rivers of fire extending to the edges of those volcanoes.
Although these lava flows may be devastating to homes near them, they move very slowly. It is not a threat to life as much as large volcanic eruptions such as those in Vesuvius in Italy or St. Helen's volcanic mountain in the United States. The Mount Vesuvius volcano destroyed the neighboring cities of Pompeii and Herculaneum when it erupted in 1979, killing thousands.
The new study, published by Nature Communications on July 28, was conducted by an international team of scientists from the United States, Britain, Ireland and Ecuador.
She studied two volcanoes of the Galapagos Islands, which are characterized by a homogeneous eruption that pushes basaltic lava flows to the surface of the Earth. Scientists analyzed the components of the microscopic crystals in the flowing lava, which eventually enabled them to reconstruct the chemical and physical properties of magma stored in the underground and found beneath those volcanoes.
The secret is in magma
The study showed that the magma components beneath these volcanoes are constantly different from the basaltic lava flowing at the surface of these volcanoes. The magma found in the depths of these volcanoes is very diverse and has a structure similar to that of the lava flowing at St. Helen volcano in the United States.
On the nature of this magma, Dr. Michael Stock, study leader at Trinity College Dublin, comments in the report published by Eurek Alert, saying, "We started the study asking why the volcanoes are monotonous and what processes have caused The volcanic lava components flowed with this constant throughout this period of time, but these volcanoes were not dull at all, as they were hiding their magma under the ground.
The team believes that these volcanoes continuously spout these homogeneous basaltic lava when the amount of magma in the Earth's interior is large enough to overcome any chemical diversity, which scientists believe can occur near hot magma columns that flow from the depths of the earth towards the surface, and define them as " Hot spots. "
Explanation of the explosive activity
However, the chemically diverse magma discovered by the team can move and ascend to the surface under certain conditions. In this case, these volcanoes - which have been accustomed to basaltic lava emission for thousands of years - will undergo unexpected changes, which could make them explosive in the future.
"Although there are no indications that the Galapagos volcanoes are going to transition from a change in the pattern of volcanic eruption soon, our results explain why the volcanic behavior of some other volcanoes has changed in the past," says Stock.
"This study will help us to understand the risks posed by volcanoes better. The stability of volcanic activity in a certain form in the past does not mean that it will always remain that way in the future," he added.
"This discovery will change the rules of the game. It will enable us to understand previously seemingly differentiated observations, such as the presence of explosive deposits in many Galapagos Volcanoes. It will also allow us to better understand volcanic behavior, which is necessary to monitor volcanic activity and assess risk. ”