LightningMay Sink MountainSummits
Rocks are pretty tough, but eventually, even the mightiest mountains crumble. Geologists usually give the credit to water and ice. But when it comes to smashing summits, a major player may be electricityin the form of lightning. Scientists have found evidence for lightning;s role in mangling mountains in the magnetic signatures of rocks, which go haywire when blasted by bolts.
I mean, these magnetic anomalies are huge. Susan Webb of the University of Witwatersrand in South Africa. And so, we don;t expect to see that, not with ice fracturing rocks. We would see that only with lightning fracturing rocks. And the fact that there;s so many tells you that;s a really important mechanism for weathering rocks.
Webb presented her results on December 18th at the annual meeting of the American Geophysical Union in San Francisco.
As a test case, she studied the magnetic signatures of rocks in the southern African country of Lesotho, a place with lots of mountains and lots of lightning. But Webb says she;s only scratched the surface. And I think as we look more and more for this, and it;s very easy to look for if we do magnetic surveys in these areas, we will see it. Then we;ll be able to tell if this is a much more widespread phenomenon.