Originally aired on September 27, 2023

In this episode, Jesse and Priscilla talk to Geophysicist Attreyee Ghosh about the fascinating topic of the disappeared ocean between India and Eurasia called Tethys. They explore how the movement of India caused the ocean to sink into the Earth’s mantle and left behind a gravity anomaly known as the gravity low. They delve into the concept of gravity anomalies and how they are related to the density structures deep within the Earth. The hosts also explore the connection between plate tectonics, earthquakes, and the formation of mountains. They highlight the importance of researching Earth’s interior to gain insights into the planet’s past and potentially discover habitable planets in other solar systems.

What is the gravity low in the northern part of the Indian Ocean?

• The gravity low is a circular area in the northern part of the Indian Ocean where gravity is lower than usual.
• It is detected through satellite measurements and indicates the presence of density structures deep within the Earth’s mantle.

How do density structures in the Earth’s mantle create gravity anomalies?

• Density structures in the mantle, caused by convection currents, result in variations in gravity on the Earth’s surface.
• Convection currents occur when hot mantle rock rises and cold outer rock sinks, creating a constant movement of material within the Earth.

Why do earthquakes and mountains occur on the Earth’s surface?

• Earthquakes occur due to the collision of tectonic plates, where one plate sinks beneath another.
• Mountains form when two plates collide and neither plate is denser than the other, causing a collision and the uplift of the Earth’s crust.

What is the significance of plate tectonics in understanding our planet and the possibility of life elsewhere?

• Plate tectonics is the unique movement of Earth’s surface, which may be responsible for the presence of water and the development of life.
• Studying plate tectonics can provide insights into the possibility of habitable planets in other solar systems.

How do scientists study the Earth’s interior without direct access?

• Seismology, the study of earthquake waves, allows scientists to indirectly study the Earth’s interior.
• Seismometers collect seismic wave data, which helps create models of the Earth’s density structures and understand its dynamic nature.

What are the implications of the research on the disappeared Tethys ocean?

• The research sheds light on the complex interactions between the Earth’s surface and its interior.
• It also highlights the ongoing search for answers regarding the origin and movement of tectonic plates, as well as the formation of oceans and mountains.