Geobulletin alpha

A Sight That Overwhelms: Dante's View and a Sense of Scale 

It's one of the most astounding viewpoints in all of North America. The Black Mountains form the eastern edge of Death Valley, and they are one of the most rugged mountain fronts in existence. In places the mountains are so steep that one cannot see the slopes at the base from the summit. Looking up from the lowest point in North America, Badwater, one can barely contemplate walking or

Living with volcanoes, and learning from the past. 

November 13th, 1985, is a date that is still etched in my memory. This was the day that the Colombian town of Armero was submerged beneath a catastrophic flood of volcanic rocks, mud and water; a lahar that had swept down from the summit of the volcano Nevado del Ruiz, erupting about 40 kilometres away. For days, terrible scenes of anguish and despair filled our television screens, as rescuers struggled desperately to help the survivors, and recover the many thousands of victims. Thirty [...]

Door 12 – Trotternish and the Macdonald Clan 

The spectacular Trotternish peninsula on the Isle of Skye is home to the famous geological sites of the Quirang and the 719m summit of the Storr. They are formed from a set of post-glacial, large-scale landslides which give the impression of … Continue reading

Friday fold: Yin-Yang at Swift Dam 

What is Matt looking at here? Matt was one of my Rockies students this summer, a geology major at the University of Virginia. Together with another UVA student and students from Mary Washington University and George Mason University, Matt embarked on a mountain-climbing hike during our evening camping at Swift Dam, near Depuyer, Montana. The hikers were treated to an extraordinary sight when they attained the summit: Click to embiggen;

Monsoon Trekking Season Is Here 

I hereby declare the Deccan Volcanics Western Ghat 2015 monsoon trekking season officially open! That picture is of the steep slopes of Fort Rajgad about an hour's drive from Pune, taken a couple of years ago. Last year the geology highlight of my treks into the Deccan Basalt countryside was this dyke with horizontal columnar joints near the summit of Fort Ghangad. Columnar joints

Greetings from Castle Rock: Humongous Hummocks Edition 

The weather did its best to ruin our plans today, but we defied it mightily. We didn't get a single glimpse of Mount St. Helens - unless you count the 2.5 cubic kilometers of the summit we hiked over. -- Read more on ScientificAmerican.com

Imaggeo on Mondays: A thermal inversion 

This week’s Imaggeo on Mondays image is brought to you by Cyril Mayaud, from the University of Graz (Austria), who writes about an impressive hike and layers of cold and warm air. Thermal inversion is a meteorological phenomenon which occurs when a layer of cold air is trapped near the Earth’s surface by an overlying layer of warmer air. This can happen frequently at the boundary between mountainous and lowland regions such as in Slovenia and last for weeks, obscuring the sun from view to [...]

Epidotized tuff, Tucson Mountains, Arizona 

I was in Tucson this past weekend for a book project meeting, and my editor and coauthor and I took a hike on Sunday morning in the Tucson Mountains to Wasson Peak. Not far from the summit, we saw an epidotized tuff, where the fiamme and pumice blobs had undergone reactions to produce pods of epidote, giving the rock a look like a sick dalmatian: This is a cool rock

Summit pump test data provides clues about impacts 

standard.net State scientists have weighed in on Summit’s controversial pump test, and appear to have some positive implications for the ski resort owners. READ

Outreach on the slopes. 

One of the beauties of living in Munich is that the Alps are, practically, on your door step. As I mentioned in one of our more recent posts, now that I am here, I’m looking forward to exploring the city, its surroundings and further afield! Making it to the top That is exactly what I did a few weekends ago. After a little research, I chose to visit the town of Garmisch-Partenkirchen, at the foothills of the Alps. I’d discovered it offered some good hiking and that the town itself was [...]

Fogo Volcano Erupts 

BREAKING: Pico Do Fogo volcano, one of the Cape Verde islands, erupted about 4 hours ago, INVOLCAN's Facebook account reported.No more information is available quite yet. A Google search turns up no news yet. The posted video showed a small ash plume a few thousand feet (estimated) high. The eruption does not appear to have occurred from the summit, so it could be a cinder cone building event. I will post more updates as they come in.Fogo volcano last erupted in 1995, with a cone building event [...]

If These Cliffs Could Talk: A Sentinel People Sometimes Miss in Yosemite 

If you saw this picture out of context, perhaps in the opening frames of an adventure movie, you might think of this cliff as being an otherworldly precipice full of allure and mystery. Maybe dragons perch on its summit, maybe buried treasure lies in a cave at its base. It's an incredible rock tower. To back up and look at this cloud filled world from a distance takes away none of

Ontake, Japan, erupts 

Ontake erupts. Photo by andreijejune as cited above.The eruption started around 11:53 a.m. Saturday, localtime (in spite of the setting in the caption above)A few hours ago, Mount Ontake 155 miles west of Tokyo, erupted, sending a steamy ash plume high into the sky. It last erupted in 2007. News is conflicting about the casualties, but at least one person has been killed,  thirty people have been injured and the Japanese are organizing to rescue an unknown number (reports vary between 41 [...]

Oregon's Mount Hood Rumbles. 

Oregon's Mount Hood, one of the famed Cascades volcanoes, has produced a few shallow earthquakes below the summit. What this means is uncertain, but it is probably typical of the volcano. Mt Hood last erupted in 1866 although there are some unconfirmed reports of eruptions in the very early 1900's. A magnitude 2.6 quake occurred below the summit at 3.7km depth, and a much shallower 2.1 one at 0.9km depth. There are currently no reports on these quakes at CVO or USGS.At this time it is unlikely [...]

Moraines in Costa Rica? Really? 

During a recent trip to Costa Rica in May, I had a conversation with some family and friends in which I uttered those words: “Moraines in Costa Rica? Really?” as they were describing a trek they’d undertaken earlier this year to the summit of Cerro Chirripó. This is the highest peak in the country (3819

Weathering on Old Rag Mountain 1: feeder dikes 

Old Rag Mountain is a distinctive mountain in the eastern Blue Ridge of Virginia, contained in a little lobe of Shenandoah National Park. It’s a great hike on several levels: (1) it’s got no trees on the summit, so you can actually get a decent view from on top, (2) it’s got a great section of full-body rock scrambling on the Ridge Trail, and (3)  it’s long (9.2 miles round

Activity at Pavlof 

“Elevated surface temperatures were detected at the summit of Pavlof volcano in satellite imagery this morning suggesting that the volcano is experiencing a low-level eruption with lava at the surface. A pilot reported a gas and ash plume drifting north at 7,000 to 8,000 feet above sea level. Based on these observations AVO is raising

Rare Melt Events at High Altitude in Greenland 

In 2012, temperatures at the summit of Greenland rose above freezing for the first time since 1889, raising questions about what led to the unusual melt

Quake Activity Detected At Inskip Hill 

About 20-25 miles WSW of Lassen Volcanic Center in Northern California lies a little known volcanic hill called Inskip. This is a Pleistocene volcanic cone complex which has had exactly no volcanic activity in historical time. Recently I have begun seeing some small quakes occur directly beneath it at a depth of about 3km, one of which occurred today at a magnitude of 2.2. This is probably nothing but it is always important to be vigilant when it comes to long dormant or presumably extinct [...]

Samples from Austin: another stretched-pebble conglomerate 

While at the University of Texas at Austin, where the Jackson School of Geosciences was hosting the Summit on the Future of Geoscience Education this past weekend, I was impressed to see a well-developed rock garden outside the student center. Here’s an example of a stretched-pebble conglomerate from that garden: Note the nice epidote boudins running down the middle. The way the foliation “flares” at the bottom suggests another boudin