Welcome to REDMAST
The Gulf of Aqaba, northern Red Sea, is recognized as a unique and easily accessible “natural marine laboratory” that provides the opportunity to study fundamental oceanographic processes in a quasi-open, deep, oligotrophic ocean environment at unprecedented spatial and temporal resolution, and subsequently, close some of the knowledge gaps related to open ocean biogeochemical processes.
The Red Sea Dust, Marine Particles and Seawater Timeseries (REDMAST) project brings together long term, highly resolved, coeval time series of dust, marine particulate matter and seawater geochemistry, whose interaction plays a critical role in the marine environment, and on wider scales, modulates global climate and the source to sink signal transfer to seafloor sediments.
REDMAST is GEOTRACES process study GIpr09. All sampling and lab work within the REDMAST project adheres to GEOTRACES work protocols.
Schematic diagram of the Gulf of Aqaba. The REDMAST project includes the operation of a sediment trap time series, dust sampling, and perform dozens of sampling cruises each year (from Torfstein et al., 2020)
Dust
Atmospheric dust loads and chemical compositions serve as a key link between global climate patterns and marine biogeo-chemical cycles. The primary source of atmospheric dust in the world today is the Sahara-Arabian desert belt. Although this source was also active during the Quaternary, the interpretation of paleo-dust records and their effects on marine ecosystems is complicated by the scarcely reported atmospheric load patterns of bioavailable phases (i.e., water and acid leachable phases) and present-day contamination of anthropogenic components.
This study reports a multi-annual time series of atmospheric dust loads and their chemical compositions collected in the north Gulf of Aqaba (north Red Sea) at a weekly to bi-weekly resolution. Major and trace element abundances in each sample are reported for three fractions: water- soluble salts, carbonates and oxides (weak acid leach), and Al-silicates.
Dust time series and record of precipitation (Torfstein et al., 2017)
Potential dust sources & and dust filters (Lapid & Torfstein, 2025)
Marine Particles
Here, we set out to study bulk and export production fluxes on a monthly- to daily- timescales at the deep oligotrophic Gulf of Aqaba, northern Red Sea, using sediment traps deployed continuously since 2014.
Particles sinking through the oceanic water column, and in particular the particulate organic carbon (POC), undergo significant changes during this process. As they gradually sink, the flux of POC is known to decrease sharply with depth due to remineralization into inorganic nutrients and dissolved organic matter. Accordingly, a central caveat in studies of past environmental changes, including the history of export production, which is the flux of POC produced in the upper ocean that escapes to deeper waters, is the linkage between the sedimentary record to that of the overlying water column, i.e., the efficiency of the water–sediment signal transfer.
Among other factors, the magnitude of export production is controlled by the availability of dissolved macro- and micro- nutrients that drive primary production, dust fluxes that not only deliver nutrients but also appear to play a role in the aggregation and subsequent sinking of particulate matter, and ocean circulation patterns. These processes are even more complex in marginal seas, where fluvial fluxes and bottom resuspension are more significant and result in episodic increases in the concentrations of particles in the water column with additional impacts on the marine environment in general, and export production in particular.
Seawater
Oceanic sampling campaigns in open oceans are typically performed across long transects and provide ‘snapshots’ of the seawater composition at the time of sampling. Due to the vast distances and complexity of working in deep open ocean environments, the spatial and temporal sampling resolution of trace metal concentrations and isotopic compositions in these marine settings is typically very low. Hence, sampling across abrupt events, such as dust storms, which might impose significant variations on the seawater composition, is very difficult and rare. Thus, the impact of very short-term events (daily, weekly) on the oceanic water column is currently very poorly known and usually only studied through laboratory experiments while in-situ observations remain scarce.
Here, we sample vertical seawater profiles across dust storms, and study their dissolved trace element concentrations and isotopic compositions (Pb, Th, Ba).
REDMAST related publications
Banc-Prandi G., Baharier N., Benaltabet T., Torfstein A., Antler G. and Fine M. (2022) Elevated temperatures reduce the resilience of the Red Sea branching coral styllophora pistillata to copper pollution. Aquatic Toxicology 244, 106096. pdf, link
Benaltabet T., Lapid G. and Torfstein A. (2023) Response of dissolved trace metals to dust storms, sediment resuspension and flash floods in the Gulf of Aqaba, northern Red Sea. Global Biogeochemical Cycles 37, e2023GB007858. link, Geotraces highlight
Benaltabet T., Lapid G. and Torfstein A. (2022) Dissolved aluminum dynamics in response to dust storms, wet deposition, and sediment resuspension in the Gulf of Aqaba, northern Red Sea. Geochimica et Cosmochimica Acta 335, 137-154. pdf, link,GEOTRACES highlight
Benaltabet T., Gunter-Hoch E. and Torfstein A. (2021) Heavy metal, rare earth element and Pb isotope dynamics in mussels during a depuration experiment in the Gulf of Aqaba, northern Red Sea. Frontiers in Marine Science 8, 669329. link.
Benaltabet T., Lapid G. and Torfstein A. (2020) Seawater Pb concentration and isotopic composition response to daily time scale dust storms in the Gulf of Aqaba, Red Sea. Marine Chemistry 227, 103895. pdf,link
Chernihovsky N., Torfstein A. and Almogi-Labin A. (2023) Daily timescale dynamics of planktonic foraminifera shell-size distributions. Frontiers in Marine Science 10:1126398. link
Chernihovsky N., Almogi-Labin A., Kienast S.S. and Torfstein A. (2020) The daily resolved temperature dependence and structure of planktonic foraminifera blooms. Scientific Reports 10(1), 1-12. link
Chernihovsky N., Torfstein A. and Almogi-Labin A. (2018) Seasonal flux patterns of planktonic foraminifera in a deep, oligotrophic, marginal sea: sediment trap time series from the Gulf of Aqaba, north Red Sea. Deep-Sea Research Part I 140, 78-94. pdf
Chien C-T., Benaltabet T., Torfstein A. and Paytan A. (2019) Contributions of atmospheric deposition to Pb concentration and isotopic composition in seawater and particulate matter in the Gulf of Aqaba, Red Sea. Environmental Science & Technology 53, 6162-6170. pdf
Hartman A., Torfstein A. and Almogi-Labin A. (2020) Climate swings in the northern Red Sea over the last 150,000 years from εNd and Mg/Ca of marine sediments. Quaternary Science Reviews 231, 106205. link, pdf
Keuter S., Koplovitz G., Torfstein A. and Frada M. (2023) Two-year seasonality (2017, 2018), export and long-term changes in coccolithophore communities in the subtropical ecosystem of the Gulf of Aqaba, Red Sea. Deep-Sea Research Part I 191, 103919. pdf, link
Kienast S.S. and Torfstein A. (2022) Evaluation of biological carbon pump metrics in the subtropical Gulf of Aqaba, northern Red Sea. Global Biogeochemical Cycles 36, e2022GB007452. pdf, link, ynet
Lapid G. and Torfstein A. (2025) Uranium isotopes and trace element distributions in atmospheric dust mineral phases from the Sahara-Arabia Desert Belt. Chemical Geology 695, 123059. pdf, link
Levy N., Torfstein A., Schiebel R., Chernihovsky N., Jochum K.P., Weis U., Stoll B. and Haug G.H., Monthly element/Ca trends and inter chamber variability in two planktic Foraminifera species: Globigerinoides ruber albus and Turborotalita clarkei from a hypersaline oligotrophic sea (in review)
Levy N., Torfstein A., Schiebel R., Chernihovsky N., Jochum K.P., Weis U., Stoll B. and Haug G.H. (2023) Temperature calibration of high Mg-calcite planktic Foraminifera shells from the hypersaline Gulf of Aqaba. Geochemistry, Geophysics, Geosystems 24, e2022GC010742. pdf, link
Mayfield K.K., Horner T.J., Torfstein A., Auro M.E., Crockford P.W. and Paytan A. (2024) Barium cycling in the Gulf of Aqaba. Frontiers in Earth Science 12, 1178487. link
Steiner Z., Benaltabet T. and Torfstein A. (2025) Dynamics of marine carbon and silica: a field study of the mechanisms controlling seawater major element concentrations. Limnology & Oceanography, doi: 10.1002/lno.12781. link
Torfstein A., Kienast S.S., Rivlin A., Isaacs S., Yarden B. and Shaked Y. (2020) Bulk and export production fluxes in the Gulf of Aqaba, northern Red Sea. ACS Earth and Space Chemistry 4(8), 1461-1479. pdf, link, Calcalist
Torfstein A. and Kienast S.S. (2018) No correlation between atmospheric dust and surface chlorophyll-a in the oligotrophic Gulf of Aqaba, northern Red Sea. Journal of Geophysical Research – biogeosciences, 123, doi.org/10.1002/2017JG004063.pdf, Eos Research Spotlight, GEOTRACES highlight
Torfstein A., Teutsch N., Tirosh O., Shaked Y., Rivlin T., Zipori A., Stein M., Lazar B. and Erel Y. (2017) Chemical characterization of atmospheric dust from a weekly time series in the north Red Sea between 2006-2010. Geochimica et Cosmochimica Acta 211, 373-393. pdf, link
