Yes, I know. It's almost October. I'm very, very late. But look at all these delicious links you have! Clear your schedule, kick back, and enjoy some superb geoscience. With most of these posts, it's not so much the words as the images that are outstanding, so do brace yourself for an abrupt loss of breath, and click through on each link...
(Special thanks to Silver Fox, who did a marvelous job collecting links!)
On June 15, 1991, Mt. Pinatubo in the Philippines erupted in a massive explosion. Science and international cooperation enabled officials to evacuate more than 75,000 people through advance notification.
In the fall of 2010, Indonesia’s Mt. Merapi had its largest eruption in over 100 years. More than 70,000 people were able to get to safety before flows of hot rocks, ash and volcanic gas rushed down the mountain toward their villages.
There are approximately 1,550 potentially active volcanoes around the world, but only one international volcano crisis response team that can rapidly deploy experts, donate and install monitoring equipment and work with counterparts to prevent eruptions from becoming disasters: the Volcano Disaster Assistance Program (VDAP).
This is a joint program between the USGS and U.S. Agency for International Development’s Office of U.S. Foreign Disaster Assistance (USAID/OFDA).
August 6th marks the 30-year anniversary for VDAP. To recognize this milestone, we are highlighting some of the major responses, showing how the program has helped save countless lives.
Why did a picturesque 2010 volcanic eruption in Iceland create so much ash?
A very informative cartoon that will help you name each kind of volcano - even the imaginary ones!
As we descend the west side of Red Pass and enter the realm of Titus Canyon proper—as opposed to being just on the Titus Canyon road—the geology becomes a little more complex than the Tertiary-to-the-north–Cambrian-to-the-south scenario that we've been seeing since leaving Tan Mountain. Just for the heck of it, I’ve shown a little of the geologic complexity of the area below, although the contacts I’ve drawn, using Google Earth’s “Add Path” tool, are merely the ones I’ve felt the need to investigate during the course of writing these little blurbs about Titus Canyon: They by no means represent all the geology, nor are they guaranteed to be accurate or precise. And I’ll probably add a few more lines before we reach Titus Canyon’s alluvial fan!
The Illgraben is a very active alpine catchment located near to the near the village of Susten (Leuk), in Canton Valais, Switzerland. This catchment is particularly interesting because it generates a large number of debris flows, some of which are very large. Since 2000 WSL has been using Illgraben as a monitoring site for debris flows. They have installed instrumentation in the catchment and in the debris flow channel. Not surprisingly, cameras are a part of the set-up, meaning that several large debris flows have been recorded. WSL has also built a warning system for the catchment in order to protect the local population.
Pierre Zufferey has recently posted a video of one such debris flow on Youtube. This event occurred on 22nd July 2016 according to the Youtube page. It is truly spectacular...
A bit south of Smilkameen - Chopaka Wildlife Area is Palmer Lake.
The lake is within a deep valley that was at least in part modified by continental glaciation. The valley was carved at least in part by glacial ice that extended well south of the lake. As the glacial ice retreated during the late stages of the last glacial period the lower end of the present Smilkameen was blocked by the Okanogan ice lobe and water flow was diverted southward though the deep valley to other outlet locations - such as the valley east of Loomis.
Sunset Bay is gorgeous, but not without fault. In fact, the whole thing is eroded around a major (inferred, but not directly observable, as far as I can tell) fault that slices through the middle of it.
When I took you on a virtual field trip to Kinkell Braes earlier this week, I didn’t mention that the sandstones are folded there, now did I?
Let me remedy that omission now...
I spent last week on the southern edge of North America. But I wasn’t surfing or beach-combing or sipping margaritas on white sand by a sparkling blue-green sea. Instead, I wandered in bright sunlight and incessant wind around ancient rocks standing above rolling sagebrush-grasslands.More precisely, I was on what once was the southern margin of North America, about 2.5 billion years ago. That was near the end of the Archean Eon, back when the Earth was still a young planet busily creating, expanding, and aggregating its continents.Fast-forward two billion years, by which time North America was shaped pretty much as it is today. The continental interior was undergoing 30 million years of major deformation, called the Laramide Orogeny. The Rocky Mountains were uplifted, including most mountain ranges in Wyoming.
To celebrate the National Parks System’s centennial, Harvard mined its map collection to find these historic gems.
Timing is everything. If one schedules a trip to the American Southwest in July or August, one may very well have to contend with the monsoons, the change in prevailing winds that brings warm humid air out of the Gulf of Mexico. The hot weather produces convection cells and intense thunderstorm activity, and flash flooding is a deadly possibility. Such flooding was in the news today in Utah and Arizona (here and here).
For many years, I scheduled river trips in the Grand Canyon that coincided with the Arizona summer monsoon, in the hope that we would be able to witness a deluge of rain that could cause torrents of water to fall over the Redwall Limestone cliffs. In my more than 80 to 85 river trips in Grand Canyon, I've seen it happen maybe only 3 times. That is until this last trip that ended on August 11.