Seismic reconnaissance survey for the ICDP proposal 'Paleoclimate, Paleoenvironment, and Paleoecology of Neogene Central America: Bridging Continents and Oceans (NICA-BRIDGE)'

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The two largest lakes in Central America, Lake Nicaragua and Lake Managua, are situated in the south-central part of Nicaragua. The location and the proposed long existence (at least Pliocene possibly Late Miocene) make these lakes promising targets for scientific drilling within the International Continental Drilling Program. Drilling objectives of global relevance, assisted by the strategic lakes' location, include therefore 1) recovery and extension of a Neotropic paleo-climate record into the past, 2) investigation of marine-lacustrine interactions in the past (connections to the oceans), in the recent and the future (channel construction), 3) the history of long tectonic and sedimentary basin (lake) development, 4) arc evolution and related hazards due to the proximity to the volcanic arc, 5) deciphering their significance as an endemic hot spot over time, 6) investigation of an important paleozogeographic event, the great American biotic interchange, and 7) the ability to combine seismology, volcanology, paleoclimate, paleoecology, and paleoenvironment in one project. Hence, in January 2015, a group of international scientists submitted an ICDP workshop proposal with the aim to develop a scientific drilling project focused on Lakes Nicaragua and Managua. The proposal was generally well received but noted a significant lack of seismic data, which makes site characterization impossible. Only very sparse seismic data have been collected in the past but failed to image the deeper subsurface due to technical problems during data acquisition and complicated depositional conditions (e.g., gas and tephras). Hence, the workshop proposal was not accepted at the current stage. The main aim of this proposal here is to collect reconnaissance seismic data of Lake Nicaragua in order to show that high-quality seismic pre-site survey data can be collected by means of modern equipment and considering the experience gained in the last decade at locations with volcanogenic lake sediments. The data will then be used for planning a full pre-site survey. The new data will also allow to investigate the basin history and seismogenic hazards in and around Lake Nicaragua.