The Seismic Wake of Costa Concordia

Abstract

On the evening of 13 January 2012, the cruise ship Costa Concordia left the port of Civitavecchia, near Rome (Italy), heading northwest toward the Italian port of Savona with 4,232 passengers and crew members aboard. A few hours later, while crossing the strait between the Island of Giglio in the Tuscan archipelago and the Monte Argentario peninsula of mainland Italy, the ship struck a rock just off the coast of the island (Fig. 1). About 90 min later, after a 180° turn, the ship capsized and partially sank in shallow waters off the port of Giglio. The shipwreck resulted in 25 casualties and, as of the writing of this paper, 7 people were still missing (the precise number is not available due to the possible presence of stow-aways). The ship now rests on her starboard side; a 50-m gash is visible on the port side (Fig. 2), with a large boulder embedded in one end. The general chronology of the shipwreck is known, thanks to publicly available Automatic Information System (AIS) data, which, when processed with dedicated software, returned the ship’s route and speed and allowed for interpolation of its unevenly spaced coded messages (Quality Positioning Services (QPS), 2012). Available uninterpreted Global Positioning System (GPS) data show the ship’s position (Fig. 3) just before and after the impact and its speed decreasing from 15 to 14 knots (27.9 to 26.1 km/h). The ship’s route is also interpolated between points by …