Abstract
The eastern Levantine basin (ELB) is an ultra-oligotrophic, warm and saline marine system, significantly affected by climate change during the past several decades. The deployment of the first moored station at the ELB (DeepLev), at 1500 m water depth, ~50 km offshore Haifa, Israel, aimed at enhancing synchronized measurements of physical and biogeochemical dynamics. The station carries an array of sediment traps and sensors that measure physical, chemical, and biological attributes along the water column. Here we describe the station and present sediment-flux data from the first 1.5 years of operation (since November 2016). We show that, despite DeepLev's offshore location and the open-sea characteristics of the water column, lateral transport from the continental margin contributes the greatest fraction of particulate flux to the seafloor at this site. This mostly occurs via intermediate nepheloid layer plumes entering the study area between depths of 180 and 800 m. Bottom currents are weak (average ± SD = 3.5 ± 2 cm s−1) and are unlikely to cause significant resuspension. Based on sedimentation rates obtained from nearby sediment cores and sediment particle fluxes sampled in the traps, calculated accumulation rates of total particulate matter and of particulate organic carbon at the seafloor were 95–108 g m−2 y−1 and 0.5–0.6 g m−2 y−1, respectively. Offshore changes in sedimentation rates and in surface sediment elemental ratios indicate that sediment originating from the continental margins is transported at least 100 km offshore.
Original language | English |
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Article number | 104663 |
Journal | Deep-Sea Research Part II: Topical Studies in Oceanography |
Volume | 171 |
DOIs | |
State | Published - Jan 2020 |
Bibliographical note
Publisher Copyright:© 2019
Funding
We thank the Mediterranean Sea Research Center of Israel (MERCI) for their partial support in establishing and running the DeepLev station. We also thank the North American Friends of IOLR and Wolfson Foundation via BIU for their financial support. We thank the IOLR electronic, sea operations and marine physics departments for invaluable help with facilities and technical operations in establishing and running the DeepLev station. We thank the captain and crew of the R/V Bat Galim. We thank the support of the engineers of the machine shop at BIU for their help in the buildup of mooring and attached devices. We thank the Israeli Ministries of Energy and Environmental Protection for their support in related activities in frame of the National Monitoring Program for Israel's Mediterranean Waters to BH, TK, ER and GSV. This project was also partly funded by Israel Science Foundation grant ISF 25/2014 to IBF and YW. We also want to thank B Goodman-Tchernov for conducting the grain size analysis, D Fink for dating the sediment cores and G Yahel for providing us with turbidity profiles data. Some of the physical contribution to this study is partly in fulfillment of a PhD thesis of Tal Ozer at the University of Haifa. Finally, we thank the two anonymous reviewers and the editor for their time and very useful comments that greatly improved the manuscript. We thank the Mediterranean Sea Research Center of Israel (MERCI) for their partial support in establishing and running the DeepLev station. We also thank the North American Friends of IOLR and Wolfson Foundation via BIU for their financial support. We thank the IOLR electronic, sea operations and marine physics departments for invaluable help with facilities and technical operations in establishing and running the DeepLev station. We thank the captain and crew of the R/V Bat Galim. We thank the support of the engineers of the machine shop at BIU for their help in the buildup of mooring and attached devices. We thank the Israeli Ministries of Energy and Environmental Protection for their support in related activities in frame of the National Monitoring Program for Israel's Mediterranean Waters to BH, TK, ER and GSV. This project was also partly funded by Israel Science Foundation grant ISF 25/2014 to IBF and YW. We also want to thank B Goodman-Tchernov for conducting the grain size analysis, D Fink for dating the sediment cores and G Yahel for providing us with turbidity profiles data. Some of the physical contribution to this study is partly in fulfillment of a PhD thesis of Tal Ozer at the University of Haifa. Finally, we thank the two anonymous reviewers and the editor for their time and very useful comments that greatly improved the manuscript.
Funders | Funder number |
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Israeli Ministries of Energy and Environmental Protection | |
Mediterranean Sea Research Center of Israel | |
North American Friends of IOLR | |
Wolfson Foundation | |
Israel Science Foundation | ISF 25/2014 |
University of Haifa |
Keywords
- DeepLev
- Lateral transport
- Levantine basin
- Moored station
- Organic carbon
- Particle fluxes
- Sediment traps
- Sedimentation