Revolutionising Rift Tectonics

Revolutionising Rift Tectonics

Richard Katz, Professor of Geodynamics was recently awarded an ERC consolidator grant of €2 million for research into “Magma-Assisted Tectonics: two-phase dynamics of oceanic and continental rifts” (RIFT-O-MAT).

Since the ‘Plate Tectonic Revolution’ of the 1960s, which transformed our understanding of plate dynamics, there has been widespread recognition of the central role of magma at divergent plate boundaries. However in almost all models of these boundaries, magmatism is treated as a by-product and is excluded from the dynamics. A thorough understanding of continental rifts and mid-ocean ridges, which are fundamental to plate tectonics, requires consistent models of magma intrusion into the lithosphere and crust. The RIFT-O-MAT project aims to develop two-phase models in which magmatism is an integral thermal, chemical, and mechanical component, and hence to better understand the basic functioning of plate tectonics.

Our current understanding of divergent boundaries comes from decades of careful observation. However without adequate models of magmatism, both old and new issues remain unresolved.  For example, in order for continents to undergo rifting, the available tectonic forces alone would be insufficient to overcome the strength of the lithosphere, indicating that magmatic intrusion is required to weaken the plates enough for rifting. Similarly, we know from bathymetric analysis of the sea floors, that even modest variations in magma supply to mid-ocean ridges are recorded by crustal magmatic intrusion and faulting. These phenomena cannot be understood and modelled in the context of single-phase flow. The RIFT-O-MAT project will break new ground by applying a theory that is inherently two-phase; one which considers the conservation of mass, momentum, and energy for a system with both liquid and solid components.

Map showing the age of oceanic crust. The red is most recent, occurring along the divergent mid-ocean plate boundaries, and blue is the oldest. Image credit: U.S. National Oceanic and Atmospheric Administration.

The open-source code developed through this study will be tested by comparing the model results with measurements of surface deformation/relief, products of seismic tomography, and geochemical analysis of lavas. In collaboration with distinguished project partners, models will be tailored to investigate the East African Rift System and Juan de Fuca ridge. Outreach will support mathematics in Africa.

Erta Ale, a continuously active basaltic shield volcano in the Afar Region of northeastern Ethiopia. This occurs within the East African Rift, a zone of Continental rifting at a developing divergent tectonic plate boundary where the African Plate is in the process of splitting into two tectonic plates, called the Somali Plate and the Nubian Plate. Photo credit: Filippo Jean.

The RIFT-O-MAT research is likely to transform our understanding of magma-assisted plate tectonics.

The President of the European Research Council, Professor Jean-Pierre Bourguignon, commented: “This ERC funding will allow ambitious scientists to establish or strengthen their teams in Europe and be truly creative in their research. Beyond a push to the grantees’ careers, this European support will offer an excellent working environment for younger researchers at doctoral and post-doctoral levels. We look forward to see many of these daring ideas come to fruition, to the benefit of Europe at large.”’

Opportunity: There is currently an opening for a Postdoctoral Research Associate position with the RIFT-O-MAT project. For more details, please click here.