A Williams College professor has been awarded a $75,000 grant to continue studying coastal impacts in Western Europe caused by storms.Since 2008, Professor Rónadh Cox and groups of students have tracked how storm waves have moved boulders as large as 430 tons and caused erosion on Ireland’s coast. She says with the archived data from those studies, this past winter made for the perfect opportunity to reach some shocking conclusions.
“It was the wettest winter in 20 years in Britain and Ireland,” Cox said. “There was a series of seven or eight phenomenally large storms that happened in a two and a half month period. When I realized that was going on I thought here’s an opportunity to do a before and after. We are the only research group that has this kind of database of photographs showing the state of the ridge at some point in time so we could go back and reoccupy all of those sites and re-photograph those locations and document exactly the changes that have happened as a consequence of these specific storms.”
Using before and after photos, GPS points and buoys in the Atlantic Ocean that measure sea levels and storm energy, the research team led by Cox was able to track onshore boulder and rock movements.
“Up until just a couple years ago people were arguing quite vehemently that rocks of the scale that we are measuring could not be moved by storm waves,” Cox explained. “That it was simply physically impossible and that the only way to accomplish that kind of work was to have a tsunami event. So we are showing unequivocally for the first time that storms can do this sort of work and that they are doing this kind of work and we are able to quantify that quite specifically and precisely.”
Cox says the largest boulder they found to have moved weighed more than 430 tons. It shifted about five meters. She adds waves moved a 19-ton rock located 17 meters above high tide and 110 meters inland up 4 and a half meters and 12 meters further inland. Although rocks get moved by waves across the globe, Cox says Ireland and the northeastern Atlantic are great testing grounds because a tsunami hasn’t struck the area in hundreds of years.
“We started looking there at these rocks because we said if we can show that they have moved in the last century or so, then we have demonstrated that they are storm deposits not tsunami deposits,” said Cox.
Junior Laura Stamp is one of the students who helped conduct the study. Comparing against earlier photographs, she says imagining how far the waves need to reach and how powerful they must have been to move the rocks to their current positions is hard to wrap your head around.
“I would just try to picture how much bigger it would have to be, not only to come up onto the cliff, but to come up with that much force to move everything,” said Stamp.
Fellow junior Caroline Atwood is doing an independent study using her experiences and the research.
“Linking the science of what’s going on with these boulder movements to the people who live on the island,” Atwood said. “Talking to the people and walking with them they know where boulders were and they know how they’ve moved over the course of a winter or several winters. They’re so in tune with how it works and that connection is really cool.”
The grant from the National Science Foundation will support further studies as well as allowing students to travel to Vancouver for The Geological Society of America’s annual meeting in October where they will present initial results. Cox says what they have already found is quite astonishing.
“I was walking around this summer with my jaw hanging somewhere down around my knees,” Cox said. “It was quite spectacular to see.”
