Earth sciences
edyong | November 4, 2009Small earthquakes in unexpected locations are often a cause for concern. The worry is that these rumbles are harbingers of bigger quakes to come. But not always - a new study suggests that many of these tremors aren't warnings, but aftershocks. In particular, those that happen in the middle of continents, far away from the major fault-lines that separate tectonic plates, probably reflect past quakes rather than future ones.
Earthquakes are a common occurrence on the boundaries between tectonic plates, and they occur at predictable spots. But they can often strike areas that are far away from…
edyong | September 28, 2009This article is reposted from the old Wordpress incarnation of Not Exactly Rocket Science. The blog is on holiday until the start of October, when I'll return with fresh material.
You don't normally hear continents described as speedy, but it's now clear that some are much faster than others. India, in particular, is the Ferrari of continents and now, scientists have discovered why.
Rewind 150 million years and the Earth looked very different. Most of the land in today's southern hemisphere were united in a single super-continent called Gondwana, including Africa, Australia, South America,…
edyong | June 8, 2009
Hundreds of thousands of years ago, one of the largest floods in Earth's history turned us into an island and changed the course of our history. Britain was not always isolated from our continental neighbours. In the Pleistocene era, we were linked to France by a land ridge called the Weald-Artois anticline that extended from Dover, across what are now the Dover Straits.
This ridge of chalk separated the North Sea on one side from the English Channel on the other. For Britain to become an island, something had to have breached the ridge.
Now, Sanjeev Gupta and colleagues from Imperial…
edyong | May 25, 2009
In 2005, corals in the large reef off the coast of Florida were saved by four hurricanes. Tropical storms seem to be unlikely heroes for any living thing. Indeed, coral reefs directly in the way of a hurricane, or even up to 90km from its centre, suffer serious physical damage. But Derek Manzello from the National Oceanic and Atmospheric Administation has found that corals just outside the storm's path reap an unexpected benefit.
Hurricanes can significantly cool large stretches of ocean as they pass overhead, by drawing up cooler water from the sea floor. And this cooling effect,…
edyong | April 17, 2009Antarctica normally conjures images of white and blue, but the frozen continent can sometimes bear more unexpected colours. Take the Taylor Glacier - when geologist Griffith Taylor first explored it a century ago, he found a bizarre reddish stain that seemed to spill waterfall-like from the glacier's snout. The area became evocatively known as Blood Falls.
The source of the blood-red colour is an underground saltwater lake that was trapped by the encroaching glacier at least 1.5 million years ago. The temperature of the water is -5 Celsius, but it's so salty that it doesn't freeze. It's…
edyong | August 12, 2008An international group of scientists have recruited a team of unlikely research assistants to help them study the Southern Ocean that surrounds Antarctica - elephant seals. Boldly going where current buoys, satellites and ships cannot, the intrepid fieldworkers will help to fill blind spots in our knowledge of this most inaccessible of oceans.
Our knowledge of the effects of climate change at the planet's poles is heavily skewed towards the Arctic. There, it's clear that the sea-ice cover is gradually shrinking. But at the opposite end of the world, in Antarctica, data is harder to come by…
edyong | February 29, 2008
The next time you watch a snowfall, just think that among the falling flakes are some that house bacteria at their core.
It's a well known fact that water freezes at 0°C, but it only does so without assistance at -40°C or colder. At higher temperatures, it needs help and relies on microscopic particles to provide a core around which water molecules can clump and crystallise. These particles act as seeds for condensation and they are rather dramatically known as "ice nucleators".
Dust and soot are reasonable ice nucleators but they are completely surpassed by bacteria, which can…
grrlscientist | November 19, 2007The fourth edition of the new Natural Sciences Blog Carnival is now available for you to read and enjoy. They saw fit to include a few pieces that I wrote -- considering that I have felt very discouraged and depressed this past month (terminal unemployment combined with lots of job rejections can do that to a person after a few years -- try it sometime if you don't believe me), it is a great compliment to see that someone out there considers my writing to be worthwhile, at least.