volcano erupting

Scientists might finally know what caused the largest volcano eruption in human history. The volcano Toba in Indonesia caused enormous devastation 73, 000 years ago. Scientists for years examined such events as their impacts on our planet and climate may be huge. Recently, the new study on this topic has been published in Nature and brought some key clues on supervolcano’s activities.

Magma flow
Magma is a complex high-temperature fluid substance with temperatures in the range 700 °C to 1300 °C

There were several massive eruptions of supervolcanos in history such as La Garita Caldera in Colorado which released 5,000 cubic kilometers of magma 27.8 million years ago or the Tambora volcano on Sumbawa Island in Indonesia wich eruption caused a global volcanic winter and 100,000 death of people. Volcanic eruptions are rated from zero to eight on a scale of explosivity, measured by the amount of ash and debris they produce. Based on the explosivity, the effects on the surrounding and climate are less to very harmful.

A group of researchers at Uppsala University have researched what cause the huge amount of magma and violently erupted it. This question is already in the debate between scientists for many years. Although it’s known that the pressure and density are the general cause of eruptions, the specific trigger was unknown.

quartz crystals
The researchers analyzed quartz crystals from Toba and found a distinct shift in the isotopic composition towards the outer rim of the crystals

Now, scientists think they found the answer in the so-called quartz crystals. Those crystals are millimeter sized and fixed in the volcanic ash and rock. Leading researcher David Budd at the Department of Earth Sciences, further explains: “Quartz crystals that grow in the magma register chemical and thermodynamical changes in the magmatic system prior to an eruption, similar to how tree rings record climate variations. When the conditions in the magma change, the crystals respond and produce distinct growth zones that record these changes.” The quartz crystals from Toba volcano appears that have different composition and weight inside and outside the volcano, which caused the drastic change in the magmatic system and therefore later eruption.

Supervolcano eruptions, besides the serious damage in the nearest area, also might cause the climate changes. Two factors are important for that: the eruption heights and the amount of sulfur dioxide contained in the dust cloud. If the eruption is large enough to reach the stratosphere the final result would be cooling the planet as the particles would block the sunlight.

Luckily for us, these supermassive eruptions are rare. Still, it is important to monitor dormant volcanos such as the one in the Yellowstone and be prepared for unwanted events.