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

UPDATE: version 2 of the bathymetric map is available at Marine Geoscience Data System (www.marine-geo.org/tools/search/entry.php?id=ChileanFjords_Piret)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.

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.

References:

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.

Moffat, C., 2014. Wind-driven
modulation of warm water supply to a proglacial fjord, Jorge Montt Glacier,
Patagonia. Geophysical Research Letters, 41, 1–8.

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.

SHOA (Servicio
Hidrográfico y Oceanográfico de la Armada de Chile), 2001. "Canal Baker y Puertos Adyacentes (Canal
Baker)", 6th ed., sheet 9100, 1:200 000, Mercator projection.

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.

Vandekerkhove, E.,
Bertrand, S., 2016. Expedition
report Paleo-GLOFs and HYDROPROX, 13 pp.

更新：版本2的 bathymetric 地形图已可在海洋地球科学数据系统（www.marine-geo.org/tools/search/entry.php?id=ChileanFjords_Piret）获取。我方呈现了 Baker-Martinez 冰川峡湾复合体（智利，48⁰S）的地形图，该图由多个数据集构建而成：包括 Baker 渠道（Harada et al., 2008）以及 Steffen 冰川峡湾和 Baker 河三角洲（Vandekerkhove & Bertrand, 2016）的多波束测深仪数据，Jorge Montt 冰川峡湾的单波束测深仪数据（Rivera et al., 2012, Moffat, 2014 及 C. Moffat 补充数据），以及来自两份 SHOA 海图（SHOA, 2001, 2008）的独立地形点。这些具有不同空间分辨率的异质数据通过 Golden Software 的 Surfer 软件中的克里金方法（3.6弧秒分辨率）进行网格化处理。我们计划在获得新的数据集后更新此图。

Baker 渠道最深处的盆地（73.8°W）的海拔以下深度达到 1075 米。向西，该渠道的海拔深度介于 450 至 750 米之间。Martinez 渠道的东部深度介于 200 至 440 米之间，向西延伸至 535 米的海拔以下。Martinez 渠道的瞄准器效应仅是网格化过程的产物，因为该区域仅有稀疏的地形数据。最深且最大的盆地（1405 米海拔以下，约 10 公里宽）位于 Messier 渠道。所有渠道均被陡峭的斜坡（20 – 40°）所夹持。整个峡湾复合体中存在横跨的山脊，形成了分隔的次级盆地（例如，Messier 渠道最深盆地以北，Baker 渠道 74.35°W 处的中心）。峡湾向其位于 Penas 港口的入口处逐渐变浅（200 – 300米海拔以下）。本地形图旨在用于区域海洋学和地质学研究项目。

参考文献：

Harada, N. 和船载科学团队，2008. MIRAI 航次报告 MR06-04 Leg 3，日本海洋地球科学技术局，横滨，176 页。

Moffat, C.，2014. 风驱动对智利巴塔哥尼亚 Jorge Montt 冰川峡湾温暖水供应的调节。地球物理研究快报，41，1–8。

Rivera, A.，Koppes, M.N.，Bravo，C.，Aravena，J.C.，2012. 小冰期冰川 Jorge Montt 的前进和后退，智利巴塔哥尼亚。过去的气候，8，403–414。

SHOA（智利海军水文和海洋观测服务），2001. “Canal Baker y Puertos Adyacentes（Canal Baker）”，第 6 版，图 9100，1:200 000，墨卡托投影。

SHOA（智利海军水文和海洋观测服务），2008. “Acceso Norte a Canal Messier – Boca de Canales a Isla Van Der Meulen”，第 2 版，图 9300，1:100 000，墨卡托投影。

Vandekerkhove, E.，Bertrand, S.，2016. Paleo-GLOFs 和 HYDROPROX 考察报告，13 页。