The MGM Laboratory tackles questions related to coastal change using micropaleontology and traditional sedimentological approaches. Our field activities range from seafloor mapping and collections to coastal surveys and archaeological excavations. We have participated across the depth range of the sea, from deep sea cruises from research ships and technical scientific diving to shallow water and beach to nearshore collections.
We are asking questions about how coastlines have changed. Where was sea level in the past and where will it be in the future? How much plastic is in the sediments? What does the sediment look like after a tsunami, and can we find tsunami markers from the past? When was an ancient harbor built, and why is it today destroyed? How do river floods change the marine system, and can past climate regimes help us understand what is happening today?
Recent excavations inside of a warehouse near Caesarea's ancient harbor have revealed anomalous layers of sand and shells deposited within a sequence of semi-articulated building stones and overlying an abandoned floor dating to the Early Islamic Period. Investigations of these deposits using grain size distribution, foraminiferal assemblage, Optically Stimulated Luminescence (OSL) dating, and relative age by portable luminescence (POSL) suggest that these sediments are marine in nature, and likely coincide with a major earthquake recorded from 749 C.E. This study will be expanded to continue searching for these anomalous layers within other Early Islamic Period areas of Caesarea in order to provide a better understanding of tsunami sedimentological characteristics in geoarchaeological contexts.
Due to a combination of high evaporation rates and low precipitation, the Dead Sea's unique geophysicochemical conditions and receding lake levels serve as an interesting grounds for environmental studies. In the spring of 2020, preliminary acoustic measurements were obtained within the lake, and dives up to water depths of 10 meters were conducted. Water samples were collected along with sediment samples from an underwater hot spring and from the Dead Sea's outer banks, extending across several previous lake levels. The physio-chemical properties and microplastic contents of the sediment samples are currently being analyzed, and proposals are being submitted to further expand this work in the future.
The Late Bronze Age eruption of Thera on Santorini resulted in one of the largest natural disasters recorded in human history, expelling pyroclastic debris flow and ash, and triggering earthquakes and tsunamis across the Eastern Mediterranean. This study aims to identify and explore the resulting tsunami deposits. Expeditions have been carried out in Turkey, Crete, and Israel, and have identified the deposits in archaeological excavations, both on land and at sea, and sediment coring campaigns. These sites will continue to be explored, and the search area will be expanded in the future.
Across the Mediterranean beaches of Israel, deposits of Glycymeris nummaria are abundant, but of unknown origin. Radiocarbon dates from these shells date the vast majority of the assemblage to 5500 to 800 BP with only rare living specimens identified during dredging activities. This study investigates the elusive nature of these Glycymeris deposits in order to determine their source of origin along the Israeli Mediterranean coast. The results of underwater archaeological excavations, sediment core analysis, and oxygen isotope paleothermometry on shell growth rings suggest that the Glycymeris originated in deeper water further offshore and were then transported to shallower water and inland, possibly by a tsunami identified from the same period. This research will continue to explore the connection between Glycymeris assemblages and possible transportation through tsunami falls across the continental shelf of Israel.
As the trade routes of the ancient Maya civilization in Mexico and Central America spanned across both land and sea, many important Maya sites are located on the coast. As is the case for coastal sites today, these sites would have been susceptible to coastal hazards and changes in sea level. As part of the Proyecto Costa Escondida, this study aims to reconstruct the coastal landscape of the Maritime Maya and to provide a better understanding of human coastal adaptation. Sediment cores and geophysical surveys were conducted in shallow water offshore Vista Alegre on the Yucatan Peninsula, and future expeditions will focus on other sites in the region to provide a more complete picture of environmental changes and coastal adaptation strategies during this time.
With the widespread use of plastics, evidence for plastic contamination is appearing at all levels of the marine environment. Macro-plastics, such as plastic bags, bottles, and take-out food containers, can be found floating in the water column, while smaller micro-plastics are present in sediments. Through the use of ROV surveys and sediment sampling expeditions, this study investigates and quantifies the macro- and micro-plastic concentrations within the water column and sediments, respectively. ROV footage and sediment samples were collected in deep water in the Mediterranean Sea, and sediment samples were also collected from the banks of the Dead Sea. These sampling campaigns will continue in the future in order to monitor changes in plastic concentrations in these regions over time.
The Pristine Seas project aims to use scientific observations and field surveys to establish marine protected areas around the world. These locations are believed to have been influenced the least by anthropogenic activities and thus are thought to represent areas that are still "pristine." Sediment samples collected from these locations are catalogued, described, and analysed (micropaleontology, geochemistry, granulometry, elemental analysis, etc.) and used to address a wide variety of questions, such as foraminiferal biodiversity in a changing global marine system, the identification of anthropogenic impacts, pollution, and climate change, and markers of marine geohazards.
Urban expansion, population growth, and development are increasing globally, including along hyper-arid coastlines- areas that are greatly affected by changes in precipitation. During infrequent rain events, devastating flash floods can occur, which, together with prolonged droughts, can have major impacts on infrastructure, ecological balance, and human life. Using marine sediment cores and in situ observations and measurements, this study quantifies sediment influx into the marine system of the Red Sea during flash flooding events. By describing both sediment transport during flash floods and the post-depositional processes that follow, this research makes it possible to reconstruct the palaeo-flood and palaeo-climate records of the Red Sea, and provides an improved understanding of the past to better prepare for future challenges.
As sea levels continue to rise globally, many are turning to studies of past sea levels to predict future changes. This study aims to reconstruct sea-level changes in the Mediterranean Sea through the combination of marine sediment core analysis, geophysical and geomorphological surveys offshore, and underwater archaeological excavation results. This multiple-proxy approach intends to incorporate several types of indicators of past sea levels in order to provide a more complete picture of the variations in the region.