Scientists drilling deep into ancient rocks in the Arizona desert say they have documented a gradual shift in Earth’s orbit that repeats regularly every 405,000 years, playing a role in natural climate swings.
|Name||Title||Fields of interest|
|Dennis V. Kent||Adjunct Senior Research Scientist||Paleomagnetism, geomagnetism and rock magnetism, and their application to geologic problems. Current interests include Cenozoic and Mesozoic geomagnetic polarity time scales; carbon cycle and paleoclimatology, paleogeography and tectonics of the Pangea supercontinent; paleofield intensity variations; and magnetic properties of sediments, oceanic basalts, and polar ice.|
May 07, 2018
November 24, 2015
Earth’s magnetic field has been getting weaker, leading some scientists to think that it might be about to flip, but the field may simply be coming down from an abnormally high intensity rather than approaching a reversal, scientists write in a new paper published online this week in the Proceedings of the National Academy of Sciences.
November 11, 2013
Tourists flock to Italy to see Michelangelo’s David and other iconic hunks of Renaissance stone, but in a trip over spring break, a group of Columbia students got to visit rocks that have shaped the world in even more profound ways. In the limestone outcrops of Italy’s Apennine Mountains, geologist Walter Alvarez collected some of the earliest evidence that a massive fireball falling from space some 66 million years ago was responsible for killing off the dinosaurs. Geologists have trekked to the region since then to study that catastrophic event as well as others imprinted in these rocks.