Geodynamics 101

Earthquakes within the plates

edited by Menno Fraters and edited by Arushi Saxena June 23, 2021

Distribution of earthquakes (circles) having magnitudes greater than 2.5 and that occurred between 18th May to 18th June, 2021 along with tectonic plate boundaries (red). The size of the circles correspond to the earthquake magnitude. Data from the USGS earthquake catalog at https://earthquake.usgs.gov/earthquakes/search/.

As fascinating as the plate tectonics and its accompanying dynamics are, continental interiors are no quiescent zones. The tectonics within these interiors are apparent in the occurrence of numerous intraplate earthquakes, and this week, EGU blog editor Arushi Saxena briefly discusses them and their mechanisms. Earthquakes are a fairly common occurrence here on Earth’s crust. Although most are ess ...[Read More]

Magnetic field generation and its reversal in dynamo models

Debarshi Majumder and edited by Jyotirmoy Paul June 9, 2021

Generation and reversal of the Earth’s magnetic field have remained one of the most controversial topics. In this week’s geodynamics 101, Debarshi Majumder, a PhD student from the Indian Institute of Science, gives a brief overview of the theory of geodynamo reversal and discusses some of the preliminary results obtained from numerical modelling. A planetary magnetic reversal is one of ...[Read More]

The Supercontinent Cycle

Tobias Rolf and edited by Kiran Chotalia May 19, 2021

This is how the Earth’s continents may(!) have assembled into a new supercontinent in ~200 Myr from now. Note that many possible scenarios have been proposed. This one is called ‘Novopangea', but others are ‘Pangea Ultima’, ‘Amasia’ or ‘Aurica’. The color coding indicates predicted tidal amplitude at 200 Myr, where deep purple corresponds to 0 meters and bright yellow to 2 meters. (From Davies et al., 2020).

From orbital, to climatic, to tectonic evolution, many aspects of the Earth’s dynamics feature high degrees of cyclicity and episodicity, which can give us important insights into how the Earth’s works. The supercontinent cycle is an example capturing the Earth’s grandest scales and this week EGU geodynamics blog editor Tobias Rolf takes a closer look at it. Pangaea. This is a familiar term to eve ...[Read More]

The boundaries of plate modelling

Jean-Christophe Wrobel-Daveau, Graeme Nicoll and edited by Lucía Pérez-Díaz March 31, 2021

The 1977 World Ocean Floor Map created by Bruce Heezen and Marie Tharp

This weeks post is all about the importance of boundaries. Plate boundaries that is. Jean-Christophe Wrobel-Daveau and Graeme Nicoll tell us why we should care where plate boundaries are and how they evolve through time, when attempting to reconstruct past plate motions. Global plate tectonic models are an incredible way to synthesise geological knowledge to gain both direct and indirect insight i ...[Read More]