Gateway exchange, climatic forcing and circulation of the Mediterranean Sea during the late Miocene: A model perspective

Abstract

The cyclic sedimentary record of the late Miocene Mediterranean shows a distinct transition from open-marine to restricted conditions, and finally to evaporitic environments associated with the Messinian Salinity Crisis. This atypical evolution has been attributed to changes in Mediterranean-Atlantic connectivity and regional climate, which has a strong precessional pulse. Tectonics and sea-level variations affect the exchange of water, salt and heat through the gateway and can therefore trigger changes in circulation and water properties in both the Atlantic Ocean and the Mediterranean Sea. Building on this qualitative knowledge of the late Miocene epoch, my objective is to improve our quantitative understanding of external forcings such as gateway size or climatic effects and their impact on the Mediterranean Sea (e.g., overturning circulation, salinity distribution and evolution). This goal is achieved by complementing the available geological/geochemical observations with a physics-based theoretical and modeling approach. During this seminar, I will address the following questions: (1) To which extent is basin salinity controlled by gateway dimensions? (2) How did the Mediterranean freshwater forcing evolve during the late Miocene?

Biography

Dirk Simon holds a BSc. and MSc. in Physics from the University of Cambridge, UK. During his Master’s thesis at the Bullard Laboratory he used Rayleigh surface tomography to investigate the upper mantle shear wave structure beneath the Cape Verde islands. This project woke his interest to learn more about processes operating on Earth.  Dirk pursued his postgraduate studies in Earth Sciences at Utrecht University in 2012. His research within the Tectonophysics group focused on past ocean circulation in the Mediterranean Sea. Although Dirk's investigations were predominantly of theoretical nature, being a member of the EU-funded training network ‘MEDGATE’ allowed him to join his colleagues in the field to explore the geology of the Mediterranean region. Within the framework of his PhD research, Dirk also spent time at Bristol University, where he worked with global climate models. During his Postdoc at the Paleomagnetic Laboratory “Fort Hoofddijk”, Dirk extended his modeling skills to the middle Miocene epoch with a focus on the Black and Caspian Sea.

Venue

Room 309, Steele Building (#03)