Taxonomy term

lucas joel

Ancient lakes may have been refuges for early life

All life needs nitrogen to build essential molecules like proteins, RNA and DNA. And to acquire nitrogen, cells need molybdenum. But molybdenum is thought to have been very scarce in Mesoproterozoic oceans 1.6 billion to 1 billion years ago, potentially stalling the evolution and diversification of life in this period, which was then entirely microscopic. New research, however, is revealing that lakes during this time contained relatively high levels of molybdenum, suggesting life may have continued evolving in those settings.
 
03 Nov 2015

The quake's impact on western thinking

The quake occurred on All Saints’ Day, and it destroyed almost every major church in Lisbon. This sparked debate among theologians about whether disasters like earthquakes were acts of divine judgment, or whether they should be seen more as indiscriminate natural phenomena.
 
01 Nov 2015

Benchmarks: November 1, 1755: Earthquake destroys Lisbon

Today, the Carmo Convent in Lisbon, Portugal, stands half destroyed; the walls remain, but the roof has been gone for 260 years. On the morning of Nov. 1, 1755, the church was packed with people attending mass for All Saints’ Day, a Catholic holiday. At about 9:30 a.m., the ground heaved, and the church’s roof fell. A magnitude-8.7 earthquake had struck. Churchgoers not crushed by falling debris fled into the streets. Across the city, candles, stoves and oil lamps fell, igniting fires that eventually burned down about half the city. Along with the shaking, the fires drove people to the banks of the Tagus River — Lisbon’s main river — and to the city’s harbor, where many boarded ships in search of safety. About 45 minutes after the shaking began, however, a 5- to 10-meter-tall tsunami entered the Tagus from the Atlantic Ocean, smashing ships against one another and against the sea walls surrounding the city.
 
01 Nov 2015

Owl pellets bridge ancient and modern ecosystems

In Homestead Cave near Utah’s Great Salt Lake, owls have been regurgitating pellets containing the undigested bones and hair of prey — typically small mammals like rodents — at a relatively constant rate since the end of the Pleistocene glaciations about 13,000 years ago. Those pellets have stacked up and fossilized in the cave to present a near-continuous glimpse into how mammal communities in this part of the Great Basin region have changed over time. Now, paleontologists examining bones in the pellets have found that, although small mammals in the region have generally been able to adapt to shifting ecosystems in the past, today, in the face of landscape-altering human activity, the mammal population is changing in unprecedented ways.
25 Oct 2015

Ancient asteroids boiled Earth's oceans

The asteroid that wiped out the remaining dinosaurs — save for the avian variety — 66 million years ago was roughly 10 kilometers wide. Long before that, however, early Earth was bombarded by many larger impactors, which pulverized Earth’s surface time and again. Now, a new study published in Geology suggests that two asteroids, dating to Archean times and estimated to be 50 to 100 kilometers in diameter, released enough energy to boil the oceans and reduce sea level by as much as 100 meters or more.
 
10 Oct 2015

Sculpting the Alps

Mountains typically get steeper the higher you climb. The European Alps are an exception: Beginning at altitudes between about 1,500 and 2,000 meters, most slopes in the range tend to become less steep with increased elevation. This is largely caused by ancient glaciers, which scoured away much of the rock from the tops of the Alps. However, the steepness of alpine slopes also decreases in areas beyond the reach of glaciers, although the reasons why have remained elusive. New research is revealing how tectonic and fluvial forces have also helped shape the Alps’ unusual topography.
 
04 Oct 2015

Benchmarks: October 4, 1915: Dinosaur National Monument Founded

While moving across the country from California to Michigan two years ago, I stopped at Dinosaur National Monument, or “Dinosaur,” which today covers 85,000 hectares and straddles the northern portion of the border between Colorado and Utah. I camped at the Green River Campground on the Utah side, and from there, Split Mountain, on the western margin of the east-west-trending Uinta Mountains, glowed violet-pink in the sunset light. 
 
04 Oct 2015

Geomedia: Documentaries: Bearded ladies doing paleontology

A paleontologist at a dig site wipes sweat from her brow, drinks from a water bottle and scratches her beard before peeling it off to expose her bare face to the cool air. If that sounds odd to you, it is meant to be. This is the Bearded Lady Project (BLP), a new documentary film project headed by filmmaker Lexi Jamieson Marsh and University of Wyoming paleontologist Ellen Currano. BLP, which launched in summer 2014 with funding from Currano’s National Science Foundation early career development grant, aims to highlight geoscience gender stereotypes, which include bearded men in plaid shirts doing dangerous fieldwork that women cannot or should not do, the filmmakers say.
 
02 Oct 2015

Dinosaurs used the same nests repeatedly

Fossil dinosaur eggs and nests offer clues about dinosaur development and behavior: Based on past work, for example, scientists have thought that some dinosaurs, like oviraptors, brooded, or sat on their eggs, much like modern birds do. Now, the results of a new study describing two fossil egg nests suggest that some dinosaurs used the same nesting sites again and again.
23 Sep 2015

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