Tuesday, March 31, 2020

Accumulating links for M6.5 earthquake 72 km west of Challis Idaho 3/31/2020 4:52 pm

An earthquake occurred in Idaho today 72 km west of Challis Idaho and about 120 km northeast of Boise Idaho. Based on the magnitude and location, I would think that it looks to be a classic Basin and Range earthquake rupturing along the mountain front south and west of Stanley Idaho (if it occurred along the Sawtooth fault--the closest active fault). But the focal mechanism is more strike-slip; we will have to wait for some updates.

The event was widely felt in the Intermontane west with light to moderate shaking in Boise. It was felt as far as Salt Lake City, Bozeman, and Spokane. The strongest ground motions appear to have been in the relatively low population Challis National Forest. Numerous aftershocks are expected.

Location of the epicenter in the Sawtooth Mountains. The yellow line to the south is the Sawtooth fault. Note the focal mechanism indicating strike-slip sense of motion


Monday, March 30, 2020

Virtual field geology exercises for GLG451 Field Geology I Spring 2020

Even before the COVID-19 crisis changed everything, I was working this semester to build some virtual options for my Field Geology I (GLG451) course. Two students are physically unable to do the field work, and then another had a crisis and missed two weekend field trips. The course has three weekend field trips and then a mini camp over spring break.

Locations of the field trips.

I decided to try to build some digital versions of the field trips using very high resolution digital elevation models and orthophotos from our SUAS systems (thanks to Tyler Scott for doing the flying and the SfM work). I wanted these to be as similar as possible to what the regular students experience so I give some initial information on the maps as well as numerous pictures from the ground and videos from the sUAS. For most of the exercises in the case of my class, I also am providing rock samples to the students of each of the mapping units.

All of the information for each of the assignments is in a long pdf which has the text assignment, links to data and images, etc. and then some explanation. It also has a topographic profile for a cross section, etc.
I am very happy to share with anyone who might find these useful. Here are the modules and the current status:

Dreamy Draw, Phoenix Mountains, AZDoneLINK
Goldfields, Superstition Mountains, AZDoneLINK
Salt River, Bush Highway, AZDoneLINK
Arnett Creek, AZDoneLINK

Example video for the Goldfields in which we fly along the path of the introductory tour:

Here is an example of one of the explanatory tutorial videos for ArcGIS:

Here is geology tour for the Salt River mapping project:

Here is longer geology tour for the Arnett Creek Spring Break mapping project:

Wednesday, March 18, 2020

Accumulating links for today's southern Salt Lake Utah area earthquake (M5.65 earthquake 4km NNE of Magna, Utah: 03/18/2020 6:09:31 AM AZ time)

A M5.7 earthquake occurred this morning and it was widely felt along the northern Wasatch Front. Numerous aftershocks have occurred and will continue. Its characteristics are consistent with the crustal extension occurring in the region (Basin and Range).

I am accumulating some links here: