colorado river – Shamskm: A site to exchange knowledge and solutions

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

By Guest PostDecember 6, 2012Scienceapatite, apatite crystals, arizona, atom, bottom, caltech, colorado boulder, colorado river, detect, earth, evolution, grand canyon, helium atom, hydrology, kenneth farley, landscape, mineral grains, phosphate mineral, radioactive decay, rebecca flowers, surface, tectonics, thermal structure, thorium, topography, university, uranium, variation, western

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…)

3-D Laser Map Shows Earthquake Zone Before and After

By Guest PostFebruary 10, 2012Science2010 mexicali earthquake, 3d post earthquake image, agricultural fields, arizona state university, austin elliott, borrego fault, China, colorado river, colorado river delta, crust, data, davis, desert floor, earth science, earthquake, earthquake zone, earthscope, fault, fault behavior, fault rupture, fault surface ruptures, floodplain, geologist, greg anderson, indiviso fault, jing liu zeng, john fletcher, ken hudnut, laser pulses, lidar, light detection and ranging, magnitude, mexicali, Mexico, michael oskin, multi fault earthquake, national science foundation, ncalm, off fault deformation, orlando teran, pescadores fault, peter gold, post earthquake topography, pre earthquake, ramon arrowsmith, ridge, rock sample, san andreas, scarp, seismic hazard, seismic wave, united states, university of california

*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…)

NASA Sees Repeating La Niña Hitting its Peak

By Guest PostJanuary 20, 2012Environmentamerican southwest, bill patzert, climate, cnes, colorado river, diva of drought, dry years, el niño, equatorial pacific, factors, jason 1, jason 2, jason altimetric satellites, la niña, NASA, near normal, ocean temperature, pacific northwest, pacific ocean, pacific sea surface, satellite, sea surface height, south america, southern california, stormy weather, united states, watershed

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…)

UA Scientists Find Evidence of Roman Period Megadrought

By Guest PostNovember 6, 2011Environment, Scienceannual growth rings of trees, bristlecone pine tree, chronology, climate, cody routson, colorado river, connie woodhouse, core, dendrochronology, extreme drought conditions, geoscientists, jonathan overpeck, la niña, medieval period, multi decade drought period, primary drainage, rio grande, rocky landscapes of alpine or near alpine mountain slopes, san juan bristlecone pines, san juan drainage, san juan rivers, second century a d, shelley littin, south central colorado, southern san juan mountains, southwestern aridity, southwestern u.s, tree bark, tropical pacific ocean, university of arizona

*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-12^th 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…)

Genetic Analysis Splits Desert Tortoise into Two Species

By Guest PostJune 29, 2011Environment, Natureagassiz desert tortoise, arizona, army physician, california, california state university dominguez hills, colorado river, desert tortoise, dna evidence, endangered species act, fish and wildlife service, fws, genetic evidence, gopherus agassizii, gopherus morafkai, habitat preferences, j g cooper, kristin berry, Mexico, morafka desert tortoise, nevada, northern arizona, robert murphy, roy averill murray, san francisco earthquake, Smithsonian, species, us army fort irwin, usaf edwards air force base, usgs, utah

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…)

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

By Guest PostJune 10, 2011Environmentalbedo, atmosphere, british columbia, bryant kealey, colorado, colorado river, ecohydrology, eric small, evan pugh, gas, grand lake, gray phase, hydrologic models, jon hammond, leslie baehr, lodgepole pine trees, meltwater, mountain pine beetles, pyranometers, river basins, rocky mountain national park, salt lake city, ski resort, snow surface albedo, snowmelt, southern wyoming, tevis blom, transmission of sunlight, university of colorado boulder

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…)

Ancient Colorado River Flowed Backwards

By Guest PostOctober 4, 2010Sciencearizona, california river, colorado river, colorado-green river system, colton formation, geologist, gulf of california, isotope, lead, mineral, mojave region, rocky mountains, southern california, steven davis, uranium, utah, zircon

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…)

Tag Archives: colorado river