Researchers Discover a Potential Link Between Climate Change and Earthquake Risk
BY: JAYLENE MATIAS
The frequency and likelihood of wildfires and droughts are rising in some regions as a result of rising temperatures. In other places, they are quickening the rate of glacial melting and intensifying storms
Within the past month we have seen wildfires destroying portions of Europe and Canada, while Beijing has seen its wettest year in at least 140 years. Looking further back, the world’s glaciers lost about 267 gigatonnes of ice annually between 2000 and 2019. Since sea levels are already rising by roughly 3.3mm annually, melting glaciers also contribute to an increase in coastal dangers including erosion and floods.
Research indicates that earthquakes and volcanic eruptions could be made worse by climate change, notably rising rainfall rates and glacial melting.
It’s interesting to note that rainfall rates and seismic activity have been linked for a long time. For instance, in the Himalayas, the annual rainfall cycle during the summer monsoon season affects the frequency of earthquakes. According to research, just 16 percent of Himalayan earthquakes happen during the monsoon season and occur in the dry pre-monsoon months of March, April, and May.
The weight of up to 4 meters of rain during the summer monsoon season compresses the crust both vertically and horizontally, stabilizing it. The effective “rebound” that occurs when this water freezes over in the winter destabilizes the area and increases the frequency of earthquakes.
Water’s weight has an effect on the Earth’s crust that extends beyond precipitation and includes glacial ice as well. About 10,000 years ago, as the previous ice age ended, large glacial ice volumes thawed, causing some of the Earth’s crust to rebound higher. Raised beaches in Scotland, some of which are up to 45 meters above present sea level, provide as evidence of this process, known as isostatic rebound.
Additionally, studies have discovered a connection between volcanic activity and variations in the glacial stress on the Earth’s crust. The Earth’s climate suddenly cooled about 5,500–4,500 years ago, and glaciers in Iceland started to advance. Analysis of volcanic ash deposits found across Europe indicates that Iceland’s volcanic activity significantly decreased during this time.
This phenomena can be attributed to the weight of glaciers crushing the Earth’s crust and the mantle beneath it (the main mass of the planet’s interior that is mostly solid). This maintained the mantle’s constituent material under greater pressure, preventing it from melting and producing the magma necessary for volcanic eruptions.
Decompression melting, in which decreased pressure promotes melting in the mantle, was only possible due to deglaciation and the resulting loss of weight on the Earth’s surface. As a result of this melting, liquid magma was created, which fueled Iceland’s following volcanic activity.
This process continues to fuel some volcanic activity in Iceland even today. Two volcanoes, Grmsvötn and Katla, regularly experience eruptions in the summer, when glaciers are receding.
Therefore, it is possible that continuous glacier retreats brought on by climate change could eventually lead to an increase in volcanic activity. The interval between glacial changes and the volcanic response, however, is comforting for the time being.
With extraordinary weather events now more common than not, the effects of a changing climate are becoming more obvious. The indirect effects of climate change on the ground underneath us are either not well acknowledged or talked about.