TY - JOUR
T1 - Evidence for Low-Temperature Diffuse Venting at North Pond, Western Flank of the Mid-Atlantic Ridge
AU - Villinger, H. W.
AU - Müller, P.
AU - Bach, W.
AU - Becker, K.
AU - Orcutt, B. N.
AU - Kaul, N.
AU - Wheat, C. G.
N1 - Funding Information:
We thank the captain and crew of RV Maria S. Merian, the pilots and engineers of the ROV Jason II, and the scientific party for their excellent support in accomplishing a challenging field program during MSM20/5 and MSM37. The funding of the shiptime by the DFG (German Science Foundation) is greatly acknowledged. Funding for this work was provided in part (ROV Jason and crew) by the U.S. National Science Foundation (OCE-1233226 to BNO) and the Center for Dark Energy Biosphere Investigations (C-DEBI; funded by NSF OCE-0939564). Thanks to S. Gaide and J. Thal for processing the baythymetric data and creating the North Pond map. Three anonymous reviewers helped to improve the manuscript. All data used can be either found in the supporting information or are archived in data repositories (www. pangaea.de and www.bco-dmo.org).
PY - 2019/6
Y1 - 2019/6
N2 - During expedition MSM37 on the German RV Maria S. Merian, bottom water temperature and sediment temperature profiles were measured in the vicinity of North Pond (western flank of Mid-Atlantic Ridge) during exploratory dives with Remotely Operated Vehicle Jason II. In addition, push cores were taken at locations with high sediment temperature gradients. We could identify two locations where sediment temperature gradients exceed 1 K/m and bottom water temperatures showed an anomaly of up to 0.04 °C above background. We interpret these observations as clear indication of low-temperature diffuse venting of fluids that have traveled through the uppermost crust. We can safely assume that the observed phenomena are widespread at ridge flank settings where sediment cover is thin or absent, and hence, we can explain the efficient heat mining on ridge flanks. Due to the difficulties of locating diffuse low-temperature discharge sites and due to the fact that discharge can occur through thin sediment cover as well as through sediment-free basement outcrops, it will be very difficult to quantify fluxes of energy and mass from low-temperature diffuse venting in ridge flank settings; however, thermal anomalies may be used to locate sites of discharge for geochemical, microbial, and hydrologic characterization.
AB - During expedition MSM37 on the German RV Maria S. Merian, bottom water temperature and sediment temperature profiles were measured in the vicinity of North Pond (western flank of Mid-Atlantic Ridge) during exploratory dives with Remotely Operated Vehicle Jason II. In addition, push cores were taken at locations with high sediment temperature gradients. We could identify two locations where sediment temperature gradients exceed 1 K/m and bottom water temperatures showed an anomaly of up to 0.04 °C above background. We interpret these observations as clear indication of low-temperature diffuse venting of fluids that have traveled through the uppermost crust. We can safely assume that the observed phenomena are widespread at ridge flank settings where sediment cover is thin or absent, and hence, we can explain the efficient heat mining on ridge flanks. Due to the difficulties of locating diffuse low-temperature discharge sites and due to the fact that discharge can occur through thin sediment cover as well as through sediment-free basement outcrops, it will be very difficult to quantify fluxes of energy and mass from low-temperature diffuse venting in ridge flank settings; however, thermal anomalies may be used to locate sites of discharge for geochemical, microbial, and hydrologic characterization.
KW - diffuse off-axis venting
KW - marine geophysics
KW - marine hydrogeology
KW - western flank of MAR
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U2 - 10.1029/2018GC008113
DO - 10.1029/2018GC008113
M3 - Article
AN - SCOPUS:85067368867
VL - 20
SP - 2572
EP - 2584
JO - Geochemistry, Geophysics, Geosystems
JF - Geochemistry, Geophysics, Geosystems
SN - 1525-2027
IS - 6
ER -