Expedition 374 and ice sheet modelling Conversation with Benjamin Keisling, scientist onboard the JOIDES Resolution during Expedition 374

Benjamin, can you please introduce you and explain your research topics? My name is Benjamin Keisling and I am part of the Sedimentology team onboard Expedition 374. I am a PhD Candidate in Geosciences at the University of Massachusetts Amherst in the USA. My PhD research centers on ice sheet modelling, and is particularly focused on how we can use proxy data to constrain uncertain processes and parameters in ice sheet models. In other words,…

Paleomagnetism for Rookies- Part two

Paleomagnetism for Rookies- Part two

From last time, it seemed like studying Earth’s ancient magnetic field was not so complicated, right? Oh, but maybe I omitted a few important details about how the paleomagnetists on board have to deal with some complications… Their ultimate target is to determine the age of the sediment. They do that by determining the polarity of Earth’s magnetic field: sometimes, it is normal (like today), sometimes it is reversed. The paleomagnetists measure the inclination (the…

Do you want to be part of the physical properties’ team on the JOIDES Resolution?

Do you want to be part of the physical properties’ team on the JOIDES Resolution?

Have a look at this blog post! Some physical properties of the cores and what they can tell us about sediments   Earth has experienced many cycles of climate change throughout its geologic history. Records of these past climates can be found in the sediments that we drill during Expedition 374. In order to learn more about past climatic conditions, we have to decipher the information recorded in the cores. Scientists on board the JOIDES…

A hole in the ship?

A hole in the ship?

During Expedition 374, the moonpool was fully opened to lower the subsea camera system to the sea floor. I have always heard about Archimedes’ principle and I know that it explains why heavy ships like the JOIDES Resolution (145 m long and 21 m wide) can float on the water without sinking. But, I didn’t think that it could be compatible with the presence of a hole like the moonpool in the bottom of the…

Tracking the age of the core

Does the grey stuff in the bowl look like common mud to you? Maybe for us but definitely not for our paleontologists! This is a very special part of the core, delivered quickly to their lab soon after the core reached the core deck. These sediments were in the core catcher, at the bottom of the core. They are the oldest sediments of each core that we recover and our paleontologists come at each “core…

The crucial role of ice shelves

The crucial role of ice shelves

What is an ice shelf? Ice shelves are floating tongues of ice that extend from grounded glaciers on land. The place where the ice sheets touch the ocean floor is called the grounding line. The grounding line is the border between the floating ice shelf and the land-based ice sheet. Ice shelves surround 75% of Antarctica’s coastline and they can be up to 2000 m thick. The Ross Ice Shelf is the largest one, and…

What will happen to sea level when this huge iceberg melts?

What will happen to sea level when this huge iceberg melts?

  ……………nothing!! You can try to use a very simple analogic model to understand. Let’s take few ice cubes (they are your iceberg!) and put them in a glass (your southern ocean) and ……………wait and see!   Nothing happens! This is so disappointing! And a little surprising for anyone who is not a physicist. So I asked a physicist for some help. It took him a least 5 min to understand what I did not…

Fulbright student Imogen Browne

Fulbright student Imogen Browne

Imogen Browne is a Fulbright student from New Zealand doing her Ph.D. in marine science at the University of South Florida. She is sailing as a physical properties specialist aboard the JOIDES Resolution during Expedition 374: Ross Sea West Antarctic Ice Sheet History. In this video she walks us through her work on the ship.

The complex interactions between ice and oceans

The complex interactions between ice and oceans

The Antarctic Circumpolar Current (ACC) is the worlds largest ocean current, and the only current that flows completely around the globe. The ACC flows eastward around the Antarctic continent and connects with the southern portions of the Atlantic, Indian, and Pacific Oceans. Nearer the continent the easterly winds cause a counter-current with a special clockwise circulation in the great indentations of the Weddell and Ross Seas and they drive to the surface the waters of…