Stories tagged Grand Canyon

That's really old: Testing done in caves along the Grand Canyon has led to an increasing of the believed age of the western section of the canyon, pegging it at around 17 million years old.
Courtesy RealbrvhrtRegular readers of the Buzz may have noticed that there are some subjects I just can’t let slide by without comment, primarily anything having to do with Vikings, smoking, steroids and my all-time favorite topic, the Grand Canyon.

And news broke today that the Grand Canyon has been pulling one over on us when it came to its age. While no amount of Botox can even begin to cover up all its wrinkles and creases, we just might have been grossly underestimating its age all these years.

The commonly accepted age for the canyon has been set at around 6 million years, primarily based on geological clues in the rocks that form the canyon’s walls.

But researchers poking around in some of the canyon’s caves now figure that the carving of the western section of the canyon might have started as far back as 17 million years ago. Also, these same researchers think that the Grand Canyon may be the ultimate combination of two canyons that cut through northern Arizona at different times, with the eastern section of the canyon being “newer.”

The first thing you have to kick out of your head when comprehending all this is that the Colorado River – which currently snakes its way along the canyon’s base – was not the original river or water drainage system to carve out the canyon. So we can’t lock our thinking into that being a major factor in the canyon’s creation.

One of the big challenges in using geology to date a canyon is that erosion and canyon carving has continued on. So the clues we can find on the canyon’s surface or walls have themselves become compromised by the elements.

That’s why researchers from the University of New Mexico went into caves along the canyon to gather more geological clues. Those clues haven’t been altered by water run-off, wind or other eroding agents.

Rock samples were taken from ten different caves along the length of the canyon. And through the use of uranium-lead isotope testing, the section of the west canyon came out to being dated as 17 million years old.

Those tests also showed that the west canyon’s formation worked both east and west. It was a long, gradual process, with the canyon being cut at a rate of about two inches per 1,000 years.

That eastern, backward erosion eventually hooked up with the eastern canyon formation action about 5 or 6 million years ago to make one huge canyon. And with the bigger canyon, the carving pace accelerated to a rate of 8 to 12 inches each 1,000 years.

Mixed into all of that were geologic forces from under the earth that were pushing rock formations in the area up at the same time erosion forces were cutting down. And that, my friends, is how you get one impressive canyon.

Also, right now the Grand Canyon is in the midst of a three-day water release at the Glen Canyon Dam that is designed to redistribute sediment in the canyon and simulate the occasional spring floods the canyon received before the Colorado River was dammed. That process has occurred several times in the past and has controversies of its own to talk about.

Here are links to couple of the other Grand Canyon related Buzz content I’ve recently posted:

• Lake Meade dropping
• Grand Canyon Skywalk to open

Feel free to share your Grand Canyon thoughts here with other Science Buzz readers.

Tags : Grand Canyon, geology, Grand Canyon age

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Drawing down: The white banks show the one-time high water mark of Lake Meade in Arizona. One group of researchers say there's a 50 percent chance the lake could dry up by the year 2021
Courtesy amyshHave you ever been to Hoover Dam? It’s a popular day trip destination for those looking for a break from the gambling in Las Vegas.

One of the impressive sights is the huge body of water stopped up behind the dam: Lake Meade. The water stretches and snakes for miles and miles upstream on the Colorado River, which cuts its way through the Grand Canyon. That reservoir of water is also the main drinking supply for much of the southwest U.S.

But analysts from San Diego's Scripps Institution of Oceanography that there’s a 50 percent chance that water will dry up by 2021. In a shorter time span, they say that there’s a 10 percent chance water in the lake will not be usable for drinking by 2013, just five years away.

The dire predictions are based on global climate change factors along with a growing demand for water in southern Nevada and southern California.

Due to current drought conditions, Lake Meade and its sister reservoir, Lake Powell upstream from the Grand Canyon, are only currently half full. Combined, they provide water to 27 million people spread over seven states.

But an official from the Central Arizona Project said that the predictions are alarmist and absurd and that the reservoirs are in no danger of drying up.

And I remember just a couple weeks ago we posted a story here on the Buzz that Rocky Mountain areas have seen wondrous amounts of snowfall this winter. A lot of that snow runoff finds its way into the Colorado River.

Do you have any deep thoughts to share on the southwest water situation? Post them here and let other Science Buzz readers know how you feel.

Tags : water, Lake Powell, Lake Meade, global climate change, dams, Colorado River, natural disaster, Grand Canyon

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Artist's view: This aerial view shows how the Skywalk will jut out over the Grand Canyon up to 70 feet from the rim. It will soar more than 4,000 feet over the bottom of the canyon.Several years ago, I was fortunate enough to spend eight days rafting through the Grand Canyon. It was simply the most awesome natural experience I’ve ever had.

Today, much to my surprise, I read that a tribe of Native Americans with a reservation along the canyon’s south rim will be opening an attraction on and over the canyon that will rattle, in my humble opinion, that natural balance of that beautiful place.

The key piece of the development Grand Canyon West will be a 70-foot long cantilevered walkway arching out over the canyon. It will be more than 4,000 feet over the Colorado River below at the canyon’s base.

The Hualapai Tribe will be charging visitors $25 a pop to walk out over the canyon on the Skyway. It hopes that the attraction will be a way to generate revenue for the tribe, whose people have a 50 percent unemployment rate living in the isolated location along the canyon. Construction of the glass-tube-bridge is nearly done and visitors should be able to start walking out on it in March.

Currently, the tribe operates flyover trips above the canyon and also pontoon boat rides on the canyon’s river. Eventually, it hopes to have a cable car tram to transport people up and down the canyon walls without the need for daylong hikes. Longer range plans call for a hotel, shopping and golf course to be developed near the Skywalk.

Natural Canyon: Here's a natural view of the Grand Canyon, the vantage point from which most visitors experience the canyon on visits there.The reservation sits outside of the national park boundaries, so the tribe doesn’t have to comply with regulations that cover national parks. But since the Colorado River flows through the park and reservation, activity on the river does need to meet park guidelines.

All that said, there seem to be a lot more questions than answers over this situation. Will this kind of development take away from natural qualities of the canyon? I think so. What do you think?

The tribe is using one of its geographical advantages to try to help improve the lives of its people. Do you think this is a good thing or a bad thing? Share your ideas and comments here.

Tags : Skywalk, Hualapai Tribe, Grand Canyon, Grand Canyon

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