A recent study joins a growing body of evidence that climate influences seismic activity.
ADVERTISEMENTThree days ago, a violent magnitude 7.3 quake struck just offshore from the Pacific nation of Vanuatu’s most populous island.
Damage was concentrated in the capital Port Vila’s downtown area, and the official figure of 10 confirmed deaths and more than 200 people injured is likely to rise, officials warned.
Perched on the Pacific Ring of Fire – a belt of tectonic plates and volcanoes – Vanuatu is regularly jolted by earthquakes, though none in living memory as large as Tuesday’s disaster.
New research suggests that climate change could be changing earthquake patterns.
Was Vanuatu’s earthquake triggered by climate change?
Vanuatu is a sprawling archipelago covering a vast expanse of the South Pacific Ocean that lies between Australia and Fiji.
Here, more than 80 coral and volcanic islands are home to 330,000 people.
The country is also among the world’s most imperilled by climate change. Earlier this month, Vanuatu led a group of small island nations in a landmark case on the matter in the top United Nations court.
Vanuatu’s location makes it particularly susceptible to earthquakes, but its seismic instability may now be exacerbated by climate change.
“Climate change is an existential threat that transcends borders, affecting all nations regardless of political ideology or geographic location,” Ralph Regenvanu, Vanuatu’s Special Envoy for Climate Change and Environment, said in a statement.
“No country can afford to keep its head in the sand any longer.”
Climate change could increase frequency of earthquakes
Research recently conducted by Colorado State University has found that climate change could be triggering more earthquakes.
It supports previous studies that provide evidence of the effect of the climate on seismic activity.
The new findings, published in the journal Geology, analysed southern Colorado’s Sangre de Cristo Mountains, a range with an active fault running along its western edge.
The teams found that the fault had been kept in place by the weight of glaciers during the last ice age. However, as the ice melted, movement along the fault increased.
Slip rates – when fractures in the earth’s crust occur -have been five times faster since the last ice age than during the time the range was covered in glaciers.
ADVERTISEMENTThis indicates that seismic activity along a fault could become more frequent as glaciers retreat.
« Climate change is happening at a rate that is orders of magnitude faster than we see in the geologic record, » first author Cece Hurtado, who led the study as her master’s thesis, said in a statement.
« We see this in the rapid mountain glacial retreats in Alaska, the Himalayas and the Alps. In many of these regions, there are also active tectonics.”
She added that their findings demonstrate that “as climate change alters ice and water loads, tectonically active areas might see more frequent fault movements and earthquakes due to rapidly changing stress conditions ».
ADVERTISEMENTUnderstanding climate’s effect on earthquakes could aid hazard assessment
The researchers’ work joins a growing body of evidence that climate influences seismic activity.
« We’ve been able to model these processes for a while, but it’s hard to find examples in nature, » said Sean Gallen, Geosciences associate professor and senior author of the study.
« This is compelling evidence. It suggests that the atmosphere and the solid earth have tight connections that we can measure in the field. »
He added that the findings provide important information about what causes earthquakes, which could be vital for hazard assessment.
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