Extreme Earth
Discover extreme events in the Earth's history that dwarf anything witnessed by humans - monster volcanoes, huge meteor impacts and epic ice ages.
The videos in this collection cover some of the most dramatic events in the Earth's history such as the time when nearly all the dry land on the planet joined together to form a supercontinent called Pangaea and a series of volcanic eruptions so powerful they covered hundreds of thousands of square kilometres of Siberia in molten lava.
Image: Artist's impression of a 500-km-diameter asteroid striking the early Earth (credit: Don Davis/NASA)
Introduction
Extreme Earth
TV clips (9)
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The tsunami from outer space
The dinosaurs may have experienced the mother of all tsunamis.
Dr Iain Stewart discusses the tsunami waves that would have been caused by the huge asteroid impact that many experts believe killed off the dinosaurs 65 million years ago. A asteroid the size of San Francisco slammed into the sea just off Mexico's Yucatan Peninsula, leaving an impact crater 112 miles across and 20 times as deep as the Grand Canyon.
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The power of a supervolcano
Scientists find evidence of a supervolcano's devastating power.
Archaeologists working in Orchard, Nebraska, found hundreds of fossilised prehistoric animals that were killed by ash from a volcanic eruption. When they traced the source of the ash, they discovered that it was a supervolcano 1,600km away in Bruneau Jarbridge, Idaho. The hotspot that powered the Bruneau Jarbridge eruption 12-10.5 million years ago caused a trail of prehistoric super-eruptions as the North American plate moved over it.
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The tropical Arctic
A methane surge in the oceans 55 million years ago warmed the Earth.
Professor Iain Stewart explains how a surge in methane, a greenhouse gas, emitted from the oceans 55 million years ago caused global warming. He describes how the rise of the Himalayas helped to bring this cooling to an end - weathering of this mighty mountain range took carbon dioxide out of the atmosphere. The exact cause of the methane surge 55 million years ago is uncertain.
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Volcanoes defeat Snowball Earth
Volcanoes may have saved an ice-bound Earth.
Dr Iain Stewart describes Snowball Earth, a period of dramatic cooling that may have started 700 million years ago. He explains how the carbon dioxide from volcanoes may have rescued our planet from an icy fate.
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The vanishing Med
Shifting continents caused the Mediterranean to dry out.
Dr Iain Stewart explains how, six million years ago, the continents of Europe and Africa moved together and cut off the Mediterranean Sea. He also explains how rivers erode the land and bring salt to the oceans.
Subjects in this collection
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The Late Heavy Bombardment ends
Asteroids and comets peppered the Earth.
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Snowball Earth
It is thought the Earth was completely covered in ice.
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Climate
Climate change has natural and manmade causes.
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Lava
Aa is a Hawaiian name for a type of lava.
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Impact craters
Asteroids and comets will continue to strike the Earth.
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Supervolcanoes
Humans have never witnessed a super-eruption.
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Ice ages
We are living during a relatively warm interglacial period.
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The Arctic
The Arctic is home to the second largest ice sheet on Earth.
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Magma
Large bodies of molten rock exist below the Earth's surface.
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Supercontinents
In the past the continents have been joined together.
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Mountain formation
Most mountains are formed at tectonic plate boundaries.
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Volcanoes
Eruptions cause widespread destruction and death but are vital for our survival.
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Oceans
Oceans cover about 71% of the Earth's surface.
News
TV professor among Queen's Birthday Honours for Devon
Broadcaster and geologist Prof Iain Stewart...
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