4 research outputs found
Geoportal del centro de datos de la UTM-CSIC
XV Jornadas de SIG Libre, 8 de junio de 2022, GironaPeer reviewe
Landslides cause tsunami waves: insights from Aysén Fjord, Chile
On 21 April 2007, an Mw 6.2 earthquake produced an unforeseen chain of events in the AysĂ©n fjord (Chilean Patagonia, 45.5°S). The earthquake triggered hundreds of subaerial landslides along the fjord flanks. Some of the landslides eventually involved a subaqueous component that, in turn, generated a series of displacement waves tsunami- like waves produced by the fast entry of a ubaerial landmass into a water body within the fjord [Naranjo et al., 2009; SepĂșlveda and Serey, 2009; Hermanns et al., 2013]. These waves, with run-ups several meters high along the shoreline, caused 10 fatalities. In addition, they severely damaged salmon farms, which constitute the main economic activity in the region, setting free millions of cultivated salmon with still unknown ecological consequences
Multiproxy characterization of sedimentary facies in a submarine sulphide mine tailings dumping site and their environmental significance: The study case of PortmĂĄn Bay (SE Spain)
Mining activities are essential to our society, but ore extraction and treatment produce waste that must be stored in safe places without harm to the environment. For a long time, seafloor disposal has been viewed as a cheap option with barely visible impacts. In PortmĂĄn Bay, SE of Spain, large amounts of tailings from open pit sulphide mining were discharged directly into the coastal sea over 33 years, thus forming a massive deposit that completely infilled the bay and expanded seawards over the inner continental shelf. Here we present the first multiproxy physicochemical characterization of the submarine tailings in PortmĂĄn Bay, mostly by using nondestructive techniques, also including pre-dumping and post-dumping sediments. Eight distinct sedimentary facies, grouped in four stratigraphic units, have been thus identified in a set of up to 4.3 m long gravity cores totalling more than 60 m. Geogenic and anthropogenic geochemical proxies consistently allow differentiating pre-dumping sediments from tailings. Potentially toxic metals if made bioavailable can reach high concentrations in units including or formed exclusively by tailings (i.e. up to 3455, 2755 and 1007 mg kgâ1 for Pb, As, and Zn, respectively). Some physical properties, such as magnetic susceptibility, are particularly useful as the tailings are rich in Fe-bearing minerals (>30% Fe in some layers). Estimated sedimentation rates show a strong gradient from proximal to distal locations, with rates in excess of 50 cm yrâ1 to less than 1 cm yrâ1 . We ultimately document the history of the transformation of PortmĂĄn Bay from an almost natural state to a new conditio
Landslides cause tsunami waves: insights from Aysén Fjord, Chile
On 21 April 2007, an Mw 6.2 earthquake produced an unforeseen chain of events in the AysĂ©n fjord (Chilean Patagonia, 45.5°S). The earthquake triggered hundreds of subaerial landslides along the fjord flanks. Some of the landslides eventually involved a subaqueous component that, in turn, generated a series of displacement waves tsunami- like waves produced by the fast entry of a ubaerial landmass into a water body within the fjord [Naranjo et al., 2009; SepĂșlveda and Serey, 2009; Hermanns et al., 2013]. These waves, with run-ups several meters high along the shoreline, caused 10 fatalities. In addition, they severely damaged salmon farms, which constitute the main economic activity in the region, setting free millions of cultivated salmon with still unknown ecological consequences