western – Shamskm: A site to exchange knowledge and solutions

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…)

CU-led Mountain Forest Study Shows Vulnerability to Climate Change

By Guest PostSeptember 16, 2012Environmentalpine, anne kelly, Arctic, atmosphere, boulder, carbon dioxide, change, climate change, colorado, data, dry, energy, ernesto trujillo, flux towers, forest greenness, ground measurement, high resolution, michael golden, mid elevation, moisture change, mountain ecosystem, mountain range, noah molotch, precipitation, radiometer, rising temperature, roger bales, satellite image, sensitivity, sierra nevada, snowmelt, tipping point, united states, university, water vapor, western, wet, year

A new University of Colorado Boulder-led study that ties forest “greenness” in the western United States to fluctuating year-to-year snowpack indicates mid-elevation mountain ecosystems are most sensitive to rising temperatures and changes in precipitation and snowmelt.

Led by CU-Boulder researcher Ernesto Trujillo and Assistant Professor Noah Molotch, the study team used the data — including satellite images and ground measurements — to identify the threshold where mid-level forests sustained primarily by moisture change to higher-elevation forests sustained primarily by sunlight and temperature. Being able to identify this “tipping point” is important because it is in the mid-level forests — at altitudes from roughly 6,500 to 8,000 feet — where many people live and play in the West and which are associated with increasing wildfires, beetle outbreaks and increased tree mortality, said Molotch. (more…)

Tag Archives: western

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

CU-led Mountain Forest Study Shows Vulnerability to Climate Change