Tag Archives: colorado river

Researchers take new look at future Colorado River flows

The Colorado River provides water for more than 30 million people in the U.S. West, so water managers have been eager to understand how climate change will affect the river’s flow. But scientific studies have produced an unsettling range of estimates, from a modest decrease of 6 percent by 2050 to a steep drop of 45 percent by then.

A new paper by researchers at the University of Washington (UW), CIRES, NOAA and other institutions across the West investigates and explains why those estimates differ and summarizes what is known about the future of this iconic Western river—key information for decision makers. (more…)

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Grand Canyon as Old as the Dinosaurs, Suggests New Study Led by CU-Boulder

An analysis of mineral grains from the bottom of the western Grand Canyon indicates it was largely carved out by about 70 million years ago — a time when dinosaurs were around and may have even peeked over the rim, says a study led by the University of Colorado Boulder.

The new research pushes back the conventionally accepted date for the formation of the Grand Canyon in Arizona by more than 60 million years, said CU-Boulder Assistant Professor Rebecca Flowers. The team used a dating method that exploits the radioactive decay of uranium and thorium atoms to helium atoms in a phosphate mineral known as apatite, said Flowers, a faculty member in CU-Boulder’s geological sciences department. (more…)

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3-D Laser Map Shows Earthquake Zone Before and After

*Geologists learn how earthquakes change the landscape — down to a few inches*

Geologists have a new tool to study how earthquakes change the landscape–down to a few inches. It’s giving scientists insights into how earthquake faults behave.

In this week’s issue of the journal Science, a team of scientists from the United States, Mexico and China reports the most comprehensive before-and-after picture yet of an earthquake zone, using data from the magnitude 7.2 event that struck near Mexicali, Mexico, in April 2010. (more…)

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NASA Sees Repeating La Niña Hitting its Peak

La Niña, “the diva of drought,” is peaking, increasing the odds that the Pacific Northwest will have more stormy weather this winter and spring, while the southwestern and southern United States will be dry.

Sea surface height data from NASA’s Jason-1 and -2 satellites show that the milder repeat of last year’s strong La Niña has recently intensified, as seen in the latest Jason-2 image of the Pacific Ocean, available at: https://sealevel.jpl.nasa.gov/images/ostm/20120108P1.jpg. (more…)

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UA Scientists Find Evidence of Roman Period Megadrought

*A new study at the UA’s Laboratory of Tree-Ring Research has revealed a previously unknown multi-decade drought period in the second century A.D. The findings give evidence that extended periods of aridity have occurred at intervals throughout our past.*

Almost nine hundred years ago, in the mid-12th century, the southwestern U.S. was in the middle of a multi-decade megadrought. It was the most recent extended period of severe drought known for this region. But it was not the first.

The second century A.D. saw an extended dry period of more than 100 years characterized by a multi-decade drought lasting nearly 50 years, says a new study from scientists at the University of Arizona. (more…)

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Genetic Analysis Splits Desert Tortoise into Two Species

RIVERSIDE, Calif. – A new study shows that the desert tortoise, thought to be one species for the past 150 years, now includes two separate and distinct species, based on DNA evidence and biological and geographical distinctions.

This genetic evidence confirms previous suspicions, based on life history analysis, that tortoises west and east of the Colorado River are two separate species. (more…)

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‘Mountain Pine Beetle Activity May Impact Snow Accumulation And Melt’

A new University of Colorado Boulder study indicates the infestation of trees by mountain pine beetles in the high country across the West could potentially trigger earlier snowmelt and increase water yields from snowpack that accumulates beneath affected trees.

Led by CU-Boulder geological sciences department doctoral student Evan Pugh, the study was undertaken near Grand Lake, Colo., adjacent to Rocky Mountain National Park, an area that has been devastated by mountain pine beetle attacks in recent years. Mountain pine beetles have killed more than 4 million acres of lodgepole pine trees in Colorado and southern Wyoming since 1996, the most severe outbreak on record. (more…)

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Ancient Colorado River Flowed Backwards

Palo Alto, CA — Geologists have found evidence that some 55 million years ago a river as big as the modern Colorado flowed through Arizona into Utah in the opposite direction from the present-day river. Writing in the October issue of the journal Geology, they have named this ancient northeastward-flowing river the California River, after its inferred source in the Mojave region of southern California. (more…)

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