By: Emma Thomas
Earth’s climate has been changing rapidly over the course of the last couple of years. Droughts have become more frequent, dangerous wildfires more prominent, and many parts of the world have experienced record-breaking temperatures; these catastrophes all result from the earth’s increasing temperature due to climate change. Now scientists believe a link has been discovered between climate change and earthquake risk in addition to volcanic activity.
Scientists have discovered that climate change, specifically events such as rising rainfall rates and glacier meltage, could also intensify activity beneath the earth’s surface, like earthquakes. According to Matthew Blackett on The Conversation, geologists have identified a relationship between rainfall rates and seismic activity; They found a pattern where the frequency of earthquakes is influenced by the annual rainfall cycle of the summer monsoon season. According to research conducted, 48% of Himalayan earthquakes strike during the drier pre-monsoon months of March, April, and May, while just 16% occur during the monsoon season.
During the season, the weight of four meters of rainfall compresses the crust vertically and horizontally, stabilizing it. When the water disappears in the drier winter months, the “rebound” destabilizes the region and increases the total number of earthquakes that occur.
Also, melting icecaps caused parts of the Earth’s crust to rebound upwards (Isostatic Rebound); the raised beaches in Scotland provide proof and evidence of the effect.
According to research, evidence from Scandinavia suggests that uplift and destabilization of the region’s tectonics triggered numerous earthquake events between 7000 and 11,000 years ago.
Furthermore, evidence has been discovered showcasing a link between climate change and volcanic activity. Approximately 4500-5,500 years ago, Earth’s climate briefly cooled, and glaciers in Iceland began to expand. Furthermore, analysis of the volcanic activity in Iceland reduced during this period. After this cooling period, however, the volcanic activity in Iceland increased after this period, still after a delay of several centuries.
The science behind this is that the glaciers’ weight compresses the Earth’s crust and the underlying mantle. This kept the material that makes up the mantle under high pressure, preventing it from melting and forming the magma required for volcanic eruptions. Unfortunately, deglaciation allowed decompression melting to occur. Here, due to the weight of the glaciers being lightened, a lower pressure is exerted on the crust and mantle, so melting occurs in the mantle. Such melting resulted in the formation of liquid magma that fueled the subsequent volcanic activity in Iceland.
Eruptions in two volcanoes (Grimsvotn and Katla) consistently occur during summer when the glaciers melt. Hence from the evidence found, it is a feasible concept that if climate change continues to occur, the earth’s temperature will increase to higher values. The frequency of volcano eruptions will also increase.