Geology

Absolute radiometric dating requires a measurable fraction of parent nucleus to remain in the sample rock. For rocks dating back to the beginning of the solar system this requires extremely long lived parent isotopes, and thus the measurement of the different rocks exact ages becomes in-precise. To be able to distinguish the relative ages of rocks from such old material and get a better time resolution short-lived isotopes that are no longer present in the rock can be used. [26] At the beginning of the solar system there were several relatively short-lived radionuclides like 26Al, 60Fe, 53Mn…

Absolute radiometric dating requires a measurable fraction of parent nucleus to remain in the sample rock. For rocks dating back to the beginning of the solar system this requires extremely long lived parent isotopes, and thus the measurement of the different rocks exact ages becomes in-precise. To be able to distinguish the relative ages of rocks from such old material and get a better time resolution short-lived isotopes that are no longer present in the rock can be used. [26] At the beginning of the solar system there were several relatively short-lived radionuclides like 26Al, 60Fe, 53Mn…

Four individual raindrops hitting their highest peaks could easily end up thousands of miles apart, one flowing north to the Beaufort Sea, another reaching the the Gulf of Mexico, a third would be absorbed into Hudson Bay to the east and the last into the vast Pacific. The raindrops that patter onto roofs, sidewalks and umbrellas during a shower or storm fall in a wide range of sizes, as anyone who pays attention can see. The explanation for this variety turns out to be much simpler than scientists thought. Experts have long thought that the size differences observed in natural…

A new impact on Jupiter is getting all the attention this week but it can happen here - and has.  Nanosized diamonds found just below the surface of Santa Rosa Island off the coast of Santa Barbara are evidence of a 'cosmic impact' approximately 12,900 years ago The hypothesis by the researchers behind the study is that fragments of a comet struck across North America at that time. "The pygmy mammoth, the tiny island version of the North American mammoth, died off at this time," said James Kennett, professor emeritus at UC Santa Barbara, who led the research that was published this week…

New research at the University of Liverpool says it is possible to develop an 'invisibility cloak' to protect buildings from earthquakes, using concentric rings of plastic which could be fitted to the Earth's surface in order to divert surface waves. It's not coming to your building any time soon.   It's a theory and they're just beginning small-scale experiments. The seismic waves produced by earthquakes include body waves which travel through the earth and surface waves which travel across it. The new technology controls the path of surface waves which are the most damaging and…

A lunar geochemist at Washington University in St. Louis says that there are still many answers to be found in moon rocks brought back by the Apollo 11 astronauts nearly 40 years ago.   And he's been studying them since then, so he should know. Randy L. Korotev, Ph.D., a research professor in the Department of Earth and Planetary Sciences in Arts&Sciences, has studied lunar samples and their chemical compositions since he was an undergraduate at the University of Wisconsin and "was in the right place at the right time" in 1969 to be a part of a team to study some of the first lunar…

A new study says both the tiger stripes and a subsurface ocean on Saturn's moon Enceladus are the result of the moon's unusual chemical composition and not a hot core, as previously believed. shedding light on the evolution of planets and guiding future space exploration. Dr Dave Stegman, a Centenary Research Fellow in the School of Earth Sciences at the University of Melbourne, led the study and says that part of the intrigue with Enceladus is that it was once presumed to be a lifeless, frozen ice ball until a water vapour plume was seen erupting from its surface in 2006.  "NASA's…

The Amazon River has been around for 11 million years ago and in its shape for the last 2.4 million years ago, according to a study on two boreholes drilled in proximity of the mouth of the Amazon River by Petrobras, the national oil company of Brazil. Until recently the Amazon Fan, a sediment column of around 10 kilometres in thickness, proved a hard nut to crack, and scientific drilling expeditions such as Ocean Drilling Program could only reach a fraction of it. Recent exploration efforts by Petrobras lifted the veil, and sedimentological and paleontological analysis on samples from two…

Two hundred million years ago, Washington was two large islands, bits of continent on the move westward, eventually bumping up against the North American continent and calling it home. Even with their new fixed address, the shifting continues; the more extreme movement has subsided laterally and continues vertically. The upthrusting of plates continues to move our mountain ranges skyward – the path of least resistance. This dynamic movement has created the landscape we see today and helped form the fossil record that tells much of Washington’s relatively recent history – the past 50 million…

Modern glaciers, such as those making up the Greenland and Antarctic ice sheets, are capable of undergoing periods of rapid change, according to new findings by paleoclimatologists at the University at Buffalo.  Their Nature Geoscience describes fieldwork to show that a prehistoric glacier in the Canadian Arctic rapidly retreated in just a few hundred years.  The proof of such rapid retreat of ice sheets provides one of few confirmations that this phenomenon occurs.   Should the same conditions recur today, they would result in sharply rising global sea levels, which would…