Active Tectonics

25 Jun 2026

Yesterday at 6 pm local time (3 pm in Arizona) pair of large earthquakes occurred in rapid succession along the northern coast of Venezuela. The first, an M7.2, ruptured at a depth of about 20 km and

5 Jun 2026

I enjoyed the opportunity to present in the spring meeting of the National Academy of Sciences Committee on Solid Earth Geophysics Spring Meeting 2026. The meeting was entitled: [Harnessing Massive

5 Jun 2026

Recently, I pulled together some notes for the [SCEC UNREST](https://www.scec.org/events/2026-scec-unrest-workshop/) Field trip in the Carrizo Plain. It was a great conversation to share with the

31 Dec 2024

There have been numerous M4-M5 earthquakes in the Awash area of Ethiopia over the last few months. This is within the Main Ethiopia Rift at its NE end where it begins to open into the Afar. There is

9 Mar 2024

I attended the **Tom Hanks, a Remembrance** [symposium](https://earthquake.usgs.gov/esc/symposium/) at the USGS in Moffett Field Oct. 17, 2024. It was a great chance to remember Tom, reflect on his

15 Dec 2023

Our [OpenTopography](https://www.opentopography.org/) project was honored at this year's AGU with the [Open Science Recognition prize](https://www.agu.org/honors/open-science): "For outstanding

15 May 2023

We regulary refer to high resolution topography (HRT) as having Digital Elevation Model (DEM) pixel sizes with their edges less than 1 m. Many raster DEMs derived from airborne laser swath mapping

1 Jul 2022

The fragility of geologic features, such as precariously balanced rocks (PBRs), can be measured by a simple parameter like α. For the case of a PBR is the smallest of the angles between the vertical

27 Dec 2021

For some "light reading" over the winter break, I have enjoyed a read of oral histories of Clarence Allen (Caltech) and Robert Wallace (USGS). [EARTHQUAKES, MINERALS AND ME: WITH THE USGS,

5 Dec 2021

I saw a link to [https://app.wombo.art/](https://app.wombo.art/) on twitter and people were posting what they got out of using their research or dissertation titles as a prompt. [It is pretty

2 Dec 2021

I recently wrote this memorial for the Geological Society of America Structural Geology and Tectonics Division (which I am now beginning my stint as chairman or soon will). That is the reason for the

24 Oct 2021

I heard in late August 2021 that Omar Abdullah was killed in the unrest that is occurring in Ethiopia. I did not learn of any details but he was an embasa--a lion--and no doubt he was there defending

11 Jun 2021

In April 2021, we finished a fairly intensive project: [AC GEO Report on Portfolio Review of EAR Seismology and Geodesy

6 Jan 2021

The Salt River in central Arizona has a spectactular set of fluvial terraces developed along it. I have lead a number of field trips along the Salt River for outreach and most importantly for our

31 Dec 2020

I became obsessed with diffusion erosion modeling in my [PhD work](http://arrowsmith410-598.asu.edu/Lectures/Lecture8/Arrowsmith_Appendix_A_1995.pdf). It is a simple (certainly oversimplified) way to

15 Dec 2020

In my classes and for research, sometimes it is useful to calculate the scalar seismic moment (M0; basically a geometric measure of the total static energy release at a 0th order). It is a function

13 Dec 2020

# Overview Our geoscience courses have benefited from plenty of course development, especially lately as we have moved online and virtual. I recently was able to invest [SESE](https://sese.asu.edu/)

25 Nov 2020

# Introduction We recently visited the Warford Ranch Volcano which is a low shield volcano that is part of the Sentinel-Arlington volcanic field of southwestern Arizona. It is about 3 million years

6 Nov 2020

Thank you for this great honor of the [Paul G. Silver Award for Outstanding Scientific Service](https://www.agu.org/Honor-and-Recognize/Honors/Section-Awards/Silver-Award). Recognition from AGU’s

16 Oct 2020

Understanding and interpreting rapidly changing Earth surface processes across a template of a rapidly urbanizing and increasingly connected world is a major challenge. Our ability to observe and

15 May 2020

An M6.4 earthquake occurred this morning in SW Nevada 56 km west of Tonopah and 202 km ESE of South Lake Tahoe. It was widely but lightly felt across southern Nevada and the central California from

22 Apr 2020

Petroleum Experts Limited has again provided the School of Earth and Space Exploration with licensed software for 2D and 3D kinematic modelling, geomechanical, fracture, and fault response modeling

1 Apr 2020

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

30 Mar 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

18 Mar 2020

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