Sci­en­tists har­vest fresh find­ings from roots of Santorini vol­cano

Kathimerini English - - Focus - BY GIOR­GOS LIALOS

A team of Greek, Amer­i­can and Bri­tish sci­en­tists are in­volved in a project to bet­ter un­der­stand the deep roots of Santorini’s vol­canic sys­tem. An­a­lyz­ing the data ob­tained two years ago dur­ing a ma­rine re­search ex­pe­di­tion, the sci­en­tists have reaped valu­able knowl­edge about the sub­ma­rine area, a ver­i­ta­ble trea­sure trove for seis­mol­o­gists and vol­ca­nol­o­gists, and while the re­sults won’t help us to pre­dict seis­mic events with the pre­ci­sion me­te­o­rol­o­gists can fore­cast the weather, they can in­di­cate which ar­eas are more prone to such events.

The team’s find­ings were re­cently pub­lished in sci­ence magazine Tectono­physics. The find­ings are based on re­search con­ducted aboard the Mar­cus Langseth, the most so­phis­ti­cated seis­mic ves­sel in the world’s aca­demic fleet, which trav­eled to Greece from the US for this project in 2015. The lead sci­en­tists of the Pro­teus project are pro­fes­sors Em­i­lie Hooft and Doug Toomey of the Univer­sity of Ore­gon, and Evi Nomikou, from the Ge­ol­ogy Depart­ment at Athens Univer­sity.

Deep anal­y­sis

Thanks to the ves­sel’s state-of-the-art equip­ment, the sci­en­tists were able to pro­duce new high-qual­ity maps of the seabed. Their re­search is cen­tered around the basin west of the Chris­tiana islets south­west of Akrotiri, and ex­tends all the way up to the basin of Amor­gos. “For the first time, we’ve mapped ac­tive fault lines in the area be­tween Santorini and Amor­gos,” says Pro­fes­sor Nomikou. “This is valu­able in­for­ma­tion. Look at the re­cent earth­quake on Lesvos. One of the prob­lems there was that the fault which pro­duced it wasn’t mapped. That’s how we know that the area east of Santorini is more ac­tive than that to its west.”

Deep anal­y­sis through the map­ping of the seabed has pro­duced lots of in­for­ma­tion. “In the area be­tween Santorini and Amor­gos, we found two un­der­wa­ter land­slides, which may be re­lated to the 7.4 mag­ni­tude earth­quake that struck the re­gion in 1956 and pro­duced a tsunami. Know­ing this is vi­tal for those who spe­cial­ize in study­ing tsunamis be­cause they can use this in­for­ma­tion for sim­u­la­tion mod­els,” adds Nomikou. As has been proven, vol­canic ac­tiv­ity is cen­tered around Kolumbo, an ac­tive un­der­sea vol­cano about 8 km north­east of Cape Kolumbo on Santorini. “We mapped a to­tal of 26 vol­canic cones and even found an old one be­tween Mi­los and Santorini, which is an area we have yet to study in more de­tail,” says the pro­fes­sor.

Map­ping the depths around Santorini has re­vealed “un­der­wa­ter ter­races” re­sem­bling those found above the sea sur­face on many Cy­cladic is­lands, used for cul­ti­va­tion. “Sys­tem­atic re­search will re­veal whether th­ese ter­races formed out of a grad­ual de­po­si­tion of ma­te­ri­als by the vol­cano or if they’re de­for­mi­ties of the depths formed by the Mi­noan era erup­tion,” says Nomikou. Map­ping the seafloor is a costly task. “You need an oceano­graphic ves­sel with state-of-theart equip­ment,” the Greek aca­demic ex­plains. “Most of Greece’s ac­tive fault lines are un­der the sea, so map­ping the seabed is im­per­a­tive if we want to have a bet­ter un­der­stand­ing of them.”

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