Earth scientists turning up the heat
Two new studies are increasing our understanding of the planet we live on and the forces that shape it…and it’s only proper for them to be from opposite ends of the world, as well.
In Massachusetts, a trio of geophysicists report in a letter to Nature that they have imaged a sharply-defined boundary between Earth’s rigid crust and the molten layer it rests upon. The nature of this “lithosphere-asthenosphere boundary” had previously been poorly understood, thought its existence has been widely accepted. The new data, obtained from recording sound waves traveling through the ground in eastern North America, shows a sharp gradient between the two layers that can most readily be explained by the presence of water or partly-molten rock at the boundary in addition to the steep increase in temperature.
And in Japan, researchers at the KamLAND subatomic particle detector are making great strides in understanding the origin of Earth’s magnetic field. They have succeeded in counting the number of antineutrinos (small particles produced during atomic decay) streaming from the planet’s core – 16.2 million per square centimeter per second, to be exact – and thus providing an exact measurement of its natural radioactivity. The nuclear decay responsible for these antineutrinos partly contributes to the vast amount of heat driving convection currents that churn Earth’s molten iron outer core and produce the magnetic field; with this measurement, we’ll now be able to determine the true extent of radioactivity’s role.
All in all, it’s been a pretty hot news week in earth science.
No Comments »
No comments yet.
RSS feed for comments on this post.
| TrackBack URI
You can also bookmark
this on del.icio.us or check the cosmos