Geology News

Since 1968, researchers have been continuously measuring Lake Tahoe’s famous water clarity and tracking how much it degrades. The degradation of water clarity is caused by runoff and development along the shores of the lake and researchers use it to gauge how healthy the lake is.

New data from UC Davis scientists show that the rate of clarity loss has significantly slowed since 2001, giving residents and scientists interested in the lake cautious optimism that almost $500 million dollars in runoff prevention and treatment may be having a positive effect on the lake.

Image Credit: wmchu on flickr.

Schladow cautioned that the data do not pinpoint a specific cause for the recent improvements, but noted that new modeling results show that runoff of fine particles from both urbanized areas and roadways around the lake are the primary factors that influence clarity levels. Fine particles scatter light and limit how far into the lake we can see.

In addition, Schladow and his UC Davis colleagues cautioned that it is difficult to use data from a small number of years (2001 to 2007) to draw conclusions about when the trend might change from a slowdown in clarity decline to an improvement in clarity. “Only with the commitment to long-term monitoring can we truly evaluate environmental changes over time,” he said.

[Via Physorg]

                  

Monday’s Sichuan Earthquake in Central China has claimed at least 12,000 lives according to authorities. Survivors are still being pulled out of the rubble and news remains slow coming out of the region.

Today’s geology picture of the day shows the damage in Beichuan county, in China’s Sichuam province.

Source: AP / Wang Jiaowen

                  

Two hosts from NPR’s afternoon show, All Things Considered, were in the Sichuan Province when the recent earthquake struck. Melissa Block and Robert Siegel were in Chengdu, approximately 60 miles from the epicenter. Melissa Block was in the middle of the interview when the earthquake struck. The audio bit of the interview is available here (just below the photo gallery). About 40 seconds into the recording you can hear the building start to shake, she ran outside narrating what she was looking at as she ran.  If you listen closely you can hear a gap in the shaking between the P and S waves.  Also, note the time when the shaking starts and when she states that the shaking is subsiding, it is well over a minute.

Having never experienced a quake of this magnitude it is quite surreal to hear. And living in the Bay Area it makes me want to check my earthquake kit.

                  

This is only tangentially related to geology (rivers and waterfalls - you could even argue geomorphology), but I just stumbled across this article on the Huffington Post that was published last month.

The most dangerous place to swim in the world? It depends on how you might classify danger: shark attacks, piranhas, rip currents, jellyfish? How about being swept over a waterfall? At Victoria Falls, on the border of Zimbabwe and Zambia - perhaps the largest waterfall in the world, visitors can swim in a pool that sits right on the brink of the waterfall, swimming right up to a ledge that drops nearly 360 feet below.

The pictures give me chills!

Source: The Daily Mail

More incredible pictures can be seen at The Daily Mail as well.

[Via Huffington Post and the Daily Mail]

                  

Today’s geology picture of the day is from the ongoing Chaiten eruption (which started unexpectedly at the beginning of this month in Chile). Ralph Harrington at The Volcanism Blog has been providing wonderful updates on the eruption.

This photo was captured on May 6 and shows electrostatic discharges as a result of the ash cloud above the volcano.

Image Credit: Carlos Gutierrez