Exploding volcanoes and river roots – Dr. Nick Mount – 27/02/12

27th February 2012

Today we are talking to Dr Nick Mount from the geography department at the University of Nottingham.

Geography. It’s not just colouring in.

Brahmaputra River

Seriously though, his research is currently saving lives all around the word. His research is split into two major parts, both related to natural hazards. The first piece of work we’ll be talking about is modelling the Brahmaputra river (known as Jamuna in Bangladesh). It is important to model this so that farmers can have better idea of what silt will be deposited during flooding and thus what crops will survive that season. Currently farmers are influenced by the government and economic factors too, which is dangerous, as planting the wrong crop can lead to failed harvest.

Ok, so we know Nick helps farmers with their livelihoods.

Now, part two.

Mount St Helen’s.

Mount St. Helens

The problem is when it erupted, Mt St Helen’s filled a whole valley (a rather large one at that) with sediment which is now flowing down stream. This has the potential to fill the river beds where it the water flow slows down and cause flooding. This becomes a huge problem when you realise there are some poorer largely populated areas down stream. So they built a silt dam to keep it in. That will stop working soon so Dr Mount is modelling the potential outcomes so they can come up with multiple solutions which will last.

Ok. So Nick is saving lives.

Is Nick the University of Nottingham’s equivalent of Superman? What other impact does his research have around the world? Can Nick colour in between the lines?

Find out on tonight’s show, 6-7pm Monday 27th February. Remember, if you have missed the show, you can always catch up with the podcast.

In Student Science today, George, Davs and Carl have made a vortex cannon. I cannot emphasise this enough. They have made. A. Vortex. Cannon. With smoke rings. Oh yes. Find out how to make your own and what the science is behind this in today’s show.


A serious side effect of the Mount St. Helens 1980 eruption was the downstream movement of enormous amounts of sediment through the North Fork Toutle River.

After the eruption, river-borne sediment increased a massive amount! It made the Toutle River one of the most sediment-laden rivers in the world.

Toutle River sediment retention structure
In the picture above you can see Mt. St. Helens in the background. In the foreground is the Toutle River Sediment Retention Structure is basically a massive dam that traps sediment before it gets any further downstream.

So we were asked what is the difference between lahars and pyroclastic flows, here are the definitions.

An example of a Lahar

A lahar is a type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris, and water. The material flows down from a volcano, typically along a river valley.

A pyroclastic flow is a fast-moving current of superheated gas (which can reach temperatures of about 1,000 °C) and rock, which reaches speeds moving away from a volcano of up to 450 mph. The flows normally hug the ground and travel downhill, or spread laterally under gravity.

An example of a pyroclastic flow
Click the images to see a larger picture!

TedX Nottingham tickets went on sale at 6pm today, you can get them online at http://tedxnottingham.org/tickets for just £10. We’ll have more information for you next week!

Dave, Nick and Emma