News from the Field: Day 6--Volcanic Hazards: Mammoth Mountain, Earthquake Fault, and the Horsehoe Lake tree kill

Today was our 'natural hazards' day. Michael led off the day with a discussion of hazards at the SNARL dorm. We started the day with a visit to Mammoth Mountain, for a long-awaited gondola trip to the mountain summit, at 11,000 feet, for a spectacular view of the Long Valley area, the high Sierra, and Yosemite Valley. The weather was gorgeous and the view magnificent. Afterwards, we headed down to a visit to the the misnamed 'Earthquake Fault' (actually a volcano-tectonic fissure), where a giant cleft has opened in the ground beneath Mammoth Mountain.  After lunch at the Earthquake Fault, we tried to visit the Horseshoe Lakes area, where a grove of pine trees has been poisoned by carbon dioxide gas emanating from Mammoth Mountain. Unfortunately, the late snow didn't cooperate--the road was blocked off several miles from the site, and a snow-covered ridge blocked our attempt to trudge to the site. We made a quick stop back in the town of Mammoth Lakes for a quick latte (and a new tire for the van!), followed by a late afternoon hike into Inyo Crater, a site of a large explosive steam eruption at the base of Mammoth Mountain. After an early dinner, the group split up into two groups--one headed to an evening SNARL guest lecture on wildlife management in California and the others headed up to the caldera for a chance to observe the US Geological Survey's laser ranging station, which monitors present-day movements of the caldera. And a special, unexpected treat--a full lunar eclipse rising over the caldera. What a view!

    May 27th
Ruben, Michael, Lily, Kat, and Rachel pose in front of the famous mammoth of Mammoth Mountain
The view from the Mammoth Mountain gondola.
Happy travellers on their way up the mountain. 
The view to the North from Mammoth provides a great view of the volcanic structures of Long Valley, with Mono Lake visible in the distance.
The group works on their sketches of the caldera....
A view of the Sierra crest--through Mia's sunglasses!

The group poses by the Mammoth Mountain sign--with a few California yahoos in the background.

The sign says it all!
The Mammoth Six--Rachel, Kat, Ruben, Lily, Emily, and Michael--with the Long Valley Caldera in the background.

After a hike to Mammoth's South Summit, Matt, John, Emily, Ruben, and Lily get a nice view of the Horseshoe Lakes.
A group pic from the Mammoth Summit--with the Sierra crest in the background.
The mountain atmosphere has a strong effect on our instructors.  John relaxes...
While Michael dances!
Josh and Matt show off their matching blue ski outfits.  (Anyone know what's hidden inside Josh's hat?)

Ryan, Lily, and Josh enjoy the view from the peak.
Check out the video of Lily's geological description of the Long Valley panorama (6 MB AVI file).
Click here 
On the way down, the gang plays 'roller coaster' in the gondola.
Michael, Kat, Ruben, Lily, and Rachel enjoy the view from the Gondola station.
After Mammoth Mountain, we stop to inspect the "Earthquake Fault", a large volcanic fissure on the flank of the mountain.
Mia, Renee, and Ruben take notes on their observations...
The group enjoys lunch on a Jeffrey pine log.
Ruben and Ryan get psyched for their gymnastics exhibition.
Check out the video of Ruben's back handspring!
Click here 
Emily shows off her tree-climbing skills.
The group is adversely affected by volcanic gases at Horseshoe Lake.
The devastating carbon dioxide tree kill at Horseshoe Lake--a sign of active movement of magma beneath the volcano.

The group discusses the history of volcanic gas seeps at Horseshoe Lake.
Liz, Matt, and Debby pose by one of the fallen trees.
The group takes a hike down to the lake.

Lily and Emily check out the anomalous thermal emissions in another, newly discovered tree kill area on the caldera's resurgent dome.
After dinner, a visit to the US Geological Survey's laser monitoring station. Stuart Wilkinson tells the group about laser measurements at Long Valley.
In the fading light and dropping temperatures, the students are still able to write in the fieldbooks.
Emily tries her hand at laser measurements.