Gridded bathymetry of the Baker-Martinez fjord complex (Chile, 48°S) v1

<p>We present a bathymetric map of the Baker-Martinez fjord complex (Chile, 48⁰S) constructed from multiple data sets: multibeam echosounder data of Baker channel (Harada et al., 2008) and of Steffen fjord and Baker river delta (Vandekerkhove & Bertrand, 2016), single beam echosounder data of Jorge Montt fjord (Rivera et al., 2012, Moffat, 2014 and additional data from C. Moffat) and individual bathymetry points from two SHOA nautical charts (SHOA, 2001, 2008). The heterogeneous data with distinct spatial resolution was gridded using the kriging method (3.6 arc-second resolution) in Surfer from Golden Software. We intend to update this map when new datasets become available. </p> <p>The deepest basin of Baker channel (73.8°W) reaches depths of 1075 m below sea level (BSL). To the west, the channel has depths ranging from 450 to 750 m BSL. Martinez channel is between 200 and 440 m deep in its eastern part and reaches depths of 535 m BSL to the west. The bullseye effect in Martinez channel is a mere artefact of the gridding procedure as there is only sparse bathymetric data available in that area. The deepest and largest basin (1405 m BSL and approx. 10 km wide) is located in Messier channel. All the channels are flanked by steep slopes (20 – 40°). Transverse ridges are present throughout the fjord complex, creating separated sub-basins (e.g. north of the deepest basin in Messier channel, in the center of Baker channel at 74.35°W). The fjord becomes shallower (200 – 300m BSL) towards its mouth in the Gulf of Penas. This bathymetric map is intended for regional oceanographic and geological research projects.</p> <p><b><u>References:</u></b></p> <p>Harada, N. and the shipboard scientific party, 2008. MIRAI cruise report MR06-04 Leg 3, Japan Agency for Marine Earth Science and Technology, Yokosuka, 176 pp.</p> <p>Moffat, C., 2014. Wind-driven modulation of warm water supply to a proglacial fjord, Jorge Montt Glacier, Patagonia. Geophysical Research Letters, <i>41</i>, 1–8.</p> <p>Rivera, A., Koppes, M.N., Bravo, C., Aravena, J.C., 2012. Little Ice Age advance and retreat of Glaciar Jorge Montt, Chilean Patagonia. Climate of the Past, 8, 403–414.</p> <p>SHOA (Servicio Hidrográfico y Oceanográfico de la Armada de Chile), 2001. "Canal Baker y Puertos Adyacentes (Canal Baker)", 6<sup>th</sup> ed., sheet 9100, 1:200 000, Mercator projection.</p> <p>SHOA (Servicio Hidrográfico y Oceanográfico de la Armada de Chile), 2008. “Acceso Norte a Canal Messier – Boca de Canales a Isla Van Der Meulen”, 2nd ed., sheet 9300, 1:100 000, Mercator projection.</p> <p>Vandekerkhove, E., Bertrand, S., 2016. Expedition report Paleo-GLOFs and HYDROPROX, 13 pp.</p>