Glaciology student wins college-wide award

posted in: Outreach, Research, Teaching | 0

Congratulations to Margot Vore for winning the “Outstanding Research Poster” award at the annual UIdaho College of Science student research fair!  Margot’s presentation was obviously very well received by all who stopped at her poster during the October 27 event.

Enthusiasts of glaciohydraulic tremor who missed the research fair can catch the latest at Margot’s oral presentation in the cryoseismology session at AGU this December, in New Orleans.  Bravo!

Margot receives her award from College of Science Dean Ginger Carney
Margot receives her award from College of Science Dean Ginger Carney

Research group presents at Northwest Glaciologists in Vancouver, BC

The UI Glacier Dynamics Group traveled to the annual meeting of Northwest Glaciologists in mid-October to present their latest research and share ideas with other regional glaciologists.  Univ. of Idaho grad students Margot Vore and Tristan Amaral made excellent presentations of their latest work.  Colleagues at the University of British Columbia and Simon Fraser University were wonderful hosts, and Vancouver, BC, treated us to glorious weather.  We’re looking forward to future years of this favorite gathering of the minds.

Margot Vore presents her research on the seismic signals produced by subglacial water flow.
Margot Vore presents her research on the seismic signals produced by subglacial water flow.

Seismometers, GPS recovered from Alaskan glacier

posted in: Field work, Research | 0

In September, UI grad student Tristan Amaral, Juneau local Mary Gianotti, and I traveled up to the Lemon Creek Glacier to recover seismic and other equipment set up at the end of June.  The seismometers, GPS receivers and pressure gauge we’d installed will help us to better understand the evolution of subglacial hydrologic systems, and their impact on glacier flow.  This work was made possible with a University of Idaho seed grant.

This fieldwork also represented the first deployment of new seismometers owned by the University of Idaho Glacier Dynamics Group, and so was a valuable test of the sensors, and their in-house constructed enclosures and power systems.  I’m happy to report that data recovery was very nearly 100% and that our station enclosures kept everything dry.  With the hard work, positive attitudes and safety consciousness of our field team, we recovered all of the sensors that had been left out, with the additional help of a little skillful helicopter piloting.  This success was in spite of the 4.2 meters of snow and ice melt that had occurred since installation, and weather at the beginning of our field time that left us rather soggy.  I’m looking forward to digging deeply into the data collected, and collaboration with our partners on this project at the University of Alaska Southeast, Caltech, and the University of Grenoble.

Welcoming new graduate student Tristan Amaral

The Glacier Dynamics lab at UIdaho welcomes Tristan Amaral this semester.  Tristan will be working on a NASA and NSF-funded project to examine the controls on calving around the Greenland Ice Sheet.  He comes to us after graduating Summa Cum Laude from the University of New Hampshire, a published paper behind him, and experience working for the Juneau Icefield Research Program (JIRP).  We’re happy to have him in Moscow!

New papers on glacier thinning, form of MSGLs, and subglacial discharge plumes

posted in: Publications, Research | 0

Several new papers published this summer exemplify the diversity of our research group’s interests and methodologies.  Thanks to the outstanding scientists and co-authors who led these efforts: Denis Felikson, Rebecca Jackson, and Matteo Spagnolo.

The first of these, published in Nature Geoscience, uses analytical analysis of glacier flow to explain the extent of inland thinning in Greenland.  This work received a variety of media coverage in the scientific and popular press, including on Boise State Public Radio and a regional newspaper, the Inlander.

The second, in Geophysical Research Letters, draws on observations of buoyant freshwater plumes in glacierized fjords and assesses their relationship to the subglacial discharge that drives them.

The third, in the Journal of Geophysical Research, uses two dimensional spectral analysis to reveal the ice stream produced bedforms consist of multiple, distinct, wavelength peaks.  These peaks coarsen down flow and are consistent with self-organizing processes.  This paper was selected as an Editor’s Highlight:

This paper reports the first application of the 2-dimensional discrete Fourier transform method to describing and analyzing the orientation-specific roughness elements of mega-scale glacial lineations (MSGL). Applying the technique to several case study examples reveals characteristic, orientation-specific roughness scales that guide process-related inferences on MSGL formation and evolution.

 

 

A figure from Spagnolo et al., 2017 shows the dominant wavelengths of mega-scale glacial lineations and their downstream variation.

U Idaho group presents and participates in international workshops

posted in: Outreach, Research | 0

It’s been a busy summer for the Glacier Dynamics group, with a number of high-profile presentations focused around glacier seismology.

In June, Tim participated in back to back workshops on Environmental Seismology, then taught during a weeklong summer course on Glacier Seismology.  During the Environmental Seismology workshop, Tim gave one of the evening keynote lectures, during which he presented an overview of his and others efforts to use seismology to better understand glaciological processes.  The workshop took place in Bavaria, Germany, and was attended by approximately 60 international scientists, many of which took part in the excellent field trip to a rockfall monitoring site in the alps.

Following the meeting in Germany, Tim flew straight to Fort Collins, CO, for the Glacier Seismology course to present on glacier hydrology, iceberg calving, and the seismic signals produced through these mechanisms.  Margot, a member of our lab, participated as a sponsored student in the Glacier Seismology course, and presented her research to date on Taku Glacier during the course.

 

A slide from the wrap-up to the Environmental Seismology workshop playfully illustrates the mechanism by which falling icebergs produce calving icequakes [Bartholomaus et al., 2012]
Environmental seismologists return from their field trip in the alps.

New paper reveals the factors that allow glacier advance

posted in: Publications, Research | 0

While glacier advance is extremely rare, study of advancing glaciers offers a more complete picture of glacier dynamics and the factors that enable such advances.  In Alaska, Yahtse Glacier is the fastest advancing glacier.  After a 40-km 20th century retreat, it has advanced 2.5 km since 1990, and is thickening by several meters per year over its terminus.  During this advance, the terminal stresses have transitioned from tensile to compressive, and the driving stresses have dropped by a factor of 3.  All of these changes at the Yahtse terminus have occurred despite net mass loss over the entire Yahtse Glacier basin, reflected by thinning in the upper reaches of the glacier.

Along flow and seasonal variations in ice speed, over the course of Yahtse Glacier’s advance.

 

We suggest that continued growth and progradation of a submarine morainal bank, and a steep icefall which dynamically isolates the terminus region from the upper basin, are critical for the sustained advance of Yahtse Glacier.

This work was led by Joey Durkin, a Ph.D. student at Cornell University, and published in Frontiers in Earth Science.

Setting up my scientific computing environment

posted in: Research | 0

I use macs at work due to their fluid interface with the unix environment, and their ability to run unix/linux programs.  I’ve recently bought a new mac, which has required that I get it set up for my scientific computing.  Below are the pieces of software I’ve needed, which help streamline your own computational workflows.

 

I start with most of Alejandro Soto’s instructions here (http://alejandrosoto.net/blog/2016/08/16/setting-up-my-mac-for-climate-research/), including iTerm, the XCode developer tools, XQuartz, Homebrew, and Anaconda (for Python).

Obspy for working with seismic data (https://github.com/obspy/obspy/wiki/Installation-via-Anaconda)

ffmpeg for working with video files and making timelapse movies – I used

brew install ffmpeg --with-fdk-aac --with-ffplay --with-freetype --with-libass --with-libquvi --with-libvorbis --with-libvpx --with-opus --with-x265

(https://trac.ffmpeg.org/wiki/CompilationGuide/MacOSX)

Octave, for my legacy Matlab code.  Octave is a free substitute for Matlab, with most of the same functionality.  I’m pleased to learn that it has a new GUI that also reproduces the Matlab GUI.  At the terminal:

brew install octave

BasicTex from Mactex-2016 for latex typesetting (because I think the full MacTex download of 2.8 Gb is obscene) (https://tug.org/mactex/morepackages.html) and then also TeXShop and LaTeXIt, from the same page.  However, because BasicTex contains so few packages, be prepared to seek out and manually install additional, necessary packages (.sty files) from ctan.org:

sudo tlmgr install <package_name>

Cyberduck to have an easy to use GUI for transferring files between different computers/servers  (https://cyberduck.io/?l=en)

The Microsoft Office Suite, available through the University of Idaho

Google Earth Pro, available as a free download, for quickly learning about field sites (https://www.google.com/earth/download/gep/agree.html)

Dropbox, Google Drive, and OneDrive, for my online file storage.

The “Be Focused” app, from the App Store, which has a timer I use to keep targeted during my days.  It’s based on the pomodoro technique.

 

Understanding subglacial hydrology through seismology

Last week, I visited the Boise State Geosciences department to give a seminar on the use of seismology to understand subglacial water flow and sediment transport.  I reviewed two of my recent papers, published in GRL (this in 2015, and this in 2016), and also presented some of the initial results from my work with graduate student, Margot Vore, from Taku Glacier.  I enjoyed getting to know some other Idaho geophysicists and identifying new opportunities for collaboration.

bartholomaus_bsu

Seismic data collected from Taku Glacier

posted in: Field work, Research | 0

I’m just back from Taku Glacier, Alaska, where UI grad student Margot Vore, UT-Austin grad student Taylor Borgfeldt, and I retrieved new seismic data from a network set up on and around the glacier.  We had a great trip, and were treated to unexpectedly phenomenal weather, with warm air, and clear, calm skies.  The seismic data we collected will form the foundation for Margot’s MS thesis, and a paper examining the temporal and spatial evolution of subglacial discharge through the melt season.  We’re looking forward to digging into the data.

This project was initiated with Jake Walter, at the UT Institute for Geophysics, and is part of a much broader collaboration on the dynamics of the Taku Glacier terminus, with glaciologists and seismologists from University of Alaska Southeast, University of Alaska Fairbanks, and Central Washington University.

 

 

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