First-of-its-Kind Study Reveals Surprising Ecological Effects of 2010 Chile EarthquakeMay 07, 2012
Yet that's exactly what researchers found in a study of the sandy beaches of south central Chile, after an 8.8-magnitude earthquake and devastating tsunami in 2010.
Their study also revealed a preview of the problems wrought by sea level rise--a major symptom of climate change.
In a scientific first, researchers from Southern University of Chile and the University of California, Santa Barbara (UCSB) were able to document the before-and-after ecological impacts of such cataclysmic occurrences.
A paper appearing today in the journal PLoS ONE details the surprising results of their study, pointing to the potential effects of natural disasters on sandy beaches worldwide.
The study is said to be the first-ever quantification of earthquake and tsunami effects on sandy beach ecosystems along a tectonically active coastal zone.
"So often you think of earthquakes as causing total devastation, and adding a tsunami on top of that is a major catastrophe for coastal ecosystems," said Jenny Dugan, a biologist at UCSB.
"As expected, we saw high mortality of intertidal life on beaches and rocky shores, but the ecological recovery at some of our sandy beach sites was remarkable.
"Plants are coming back in places where there haven't been plants, as far as we know, for a very long time. The earthquake created sandy beach habitat where it had been lost. This is not the initial ecological response you might expect from a major earthquake and tsunami."
Their findings owe a debt to serendipity.
The researchers were knee-deep in a study supported by FONDECYT in Chile and the U.S. National Science Foundation's (NSF) Santa Barbara Coastal Long-Term Ecological Research (LTER) site of how sandy beaches in Santa Barbara and south central Chile respond, ecologically, to man-made armoring such as seawalls and rocky revetments.
By late January, 2010, they had surveyed nine beaches in Chile.
The earthquake hit in February.
Recognizing a unique opportunity, the scientists changed gears and within days were back on the beaches to reassess their study sites in the catastrophe's aftermath.
They've returned many times since, documenting the ecological recovery and long-term effects of the earthquake and tsunami on these coastlines, in both natural and human-altered settings.
"It was fortunate that these scientists had a research program in the right place--and at the right time--to allow them to determine the responses of coastal species to natural catastrophic events," said David Garrison, program director for NSF's coastal and ocean LTER sites.
The magnitude and direction of land-level change resulting from the earthquake and exacerbated by the tsunami brought great effects, namely the drowning, widening and flattening of beaches.
The drowned beach areas suffered mortality of intertidal life; the widened beaches quickly saw the return of biota that had vanished due to the effects of coastal armoring.
"With the study in California and Chile, we knew that building coastal defense structures, such as seawalls, decreases beach area, and that a seawall results in the decline of intertidal diversity," said lead paper author Eduardo Jaramillo of the Universidad Austral de Chile.
"But after the earthquake, where significant continental uplift occurred, the beach area that had been lost due to coastal armoring has now been restored," said Jaramillo. "And the re-colonization of the mobile beach fauna was underway just weeks afterward."
The findings show that the interactions of extreme events with armored beaches can produce surprising ecological outcomes. They also suggest that landscape alteration, including armoring, can leave lasting footprints in coastal ecosystems.
"When someone builds a seawall, beach habitat is covered up with the wall itself, and over time sand is lost in front of the wall until the beach eventually drowns," said Dugan.
"The semi-dry and damp sand zones of the upper and mid-intertidal are lost first, leaving only the wet lower beach zones. This causes the beach to lose diversity, including birds, and to lose ecological function."
Sandy beaches represent about 80 percent of the open coastlines globally, said Jaramillo.
"Beaches are very good barriers against sea level rise. They're important for recreation--and for conservation."
The National Science Foundation (NSF)
Related Earthquake Current Events and Earthquake News Articles
Re-thinking Southern California earthquake scenarios in Coachella Valley, San Andreas Fault
New three-dimensional (3D) numerical modeling that captures far more geometric complexity of an active fault segment in southern California than any other, suggests that the overall earthquake hazard for towns on the west side of the Coachella Valley such as Palm Springs and Palm Desert may be slightly lower than previously believed.
UW team explores large, restless volcanic field in Chile
If Brad Singer knew for sure what was happening three miles under an odd-shaped lake in the Andes, he might be less eager to spend a good part of his career investigating a volcanic field that has erupted 36 times during the last 25,000 years.
University of Minnesota engineers make sound loud enough to bend light on a computer chip
During a thunderstorm, we all know that it is common to hear thunder after we see the lightning. That's because sound travels much slower (768 miles per hour) than light (670,000,000 miles per hour).
Caltech geologists discover ancient buried canyon in South Tibet
A team of researchers from Caltech and the China Earthquake Administration has discovered an ancient, deep canyon buried along the Yarlung Tsangpo River in south Tibet, north of the eastern end of the Himalayas.
Seismic Hazard in the Puget Lowland, Washington State, USA
Seismic hazards in the Puget Lowland of northwestern Washington include deep earthquakes associated with the Cascadia subduction zone and shallow earthquakes associated with crustal faults across the region.
Study shows tectonic plates not rigid, deform horizontally in cooling process
The puzzle pieces of tectonic plates that make up the outer layer of the earth are not rigid and don't fit together as nicely as we were taught in high school.
Study of Chile earthquake finds new rock structure that affects earthquake rupture
Researchers from the University of Liverpool have found an unusual mass of rock deep in the active fault line beneath Chile which influenced the rupture size of a massive earthquake that struck the region in 2010.
'Integrated Play Groups' help children with autism
It's an often agonizing challenge facing any parent of a child with autism: How can I help my son or daughter socialize with his or her typically developing peers? The solution, SF State's Pamela Wolfberg found, may lie in a different type of playgroup that focuses on collaborative rather than adult-directed activities.
Radiation exposure linked to aggressive thyroid cancers
For the first time, researchers have found that exposure to radioactive iodine is associated with more aggressive forms of thyroid cancer, according to a careful study of nearly 12,000 people in Belarus who were exposed when they were children or adolescents to fallout from the 1986 Chernobyl nuclear power plant accident.
Rising above the risk: America's first tsunami refuge
Washington's coast is so close to the seismically active Cascadia Subduction Zone that if a megathrust earthquake were to occur, a tsunami would hit the Washington shoreline in just 25 minutes.
More Earthquake Current Events and Earthquake News Articles