1st with 102 votes: Benjamin Murphy - Oregon State University
Using EarthScope magnetotelluric (MT) data from the southeastern United States, we found a highly anomalous electrically resistive region in the uppermost mantle beneath the Piedmont physiographic province. The northwestern edge of this unusual structure robustly corresponds to the sharp southeastern edge of the modern Appalachian Mountains, as shown here. We interpret this mantle anomaly as having played a significant role in the rejuvenation and persistence of modern Appalachian topography. (From Murphy & Egbert, Earth Planetary Science Letters, 2017.)
2nd with 69 votes: Ted Channel - TC1 School Seismometers, Idaho
“A Busy Seismic Day in New Zealand, Nov. 13, 2016 ”
3rd with 35 votes: Bill Hammond - University of Nevada, Reno
Earthquake ghosts and mountain uplift. Map of California and Nevada with result of applying the GPS Imaging algorithm (Hammond et al., 2016) to the vertical MIDAS rates (Blewitt et al., 2016) superimposed on topography. GPS data are from the NSF EarthScope Plate Boundary Observatory and other networks in the western United States. Color scale is in mm/yr, positive (red) upward, negative (blue) downward, saturated at color scale limits. Red area in north-central Nevada is the mantle relaxation signal of past earthquakes on the Central Nevada Seismic Belt that ruptured between 1915 and 1954. Red between the Sierra Nevada crest and Central Valley of California shows active uplift of the range attributable to both tectonic forces and the loss of water load during drought conditions.
Victoria Hilke - High School Student at Santana High School, San Diego & Intern at Scripps Institution of Oceanography
Avatars for the TILT TRIVIA app (available for Android and iOS devices). These avatars were specifically designed for use in the TILT TRIVIA fracking game. From top to bottom, and left to right, these avatars depict: an oil drop, an oil tycoon, an Oklahoma talisman, a geoid, seismogram gal, work boots adorned with a flower, donkey w/hard hat as a play on words of the “oil donkey” machinery used in oil extraction, and a water droplet.
Yinzhi Wang - Indiana University
A three-dimensional, vector-formed image volume of P to S scattering potential under all of the lower 48 states are produced with the plane wave migration (PWMIG) method, after processing 2,458,973 three-component seismograms from all USArray stations with and 141,080 pairs of high-quality receiver functions from the EarthScope Automated Receiver Survey with the generalized iterative deconvolution method. The cross-section cutting through the PWMIG imaging volume with orientation along the direction of subduction shows the normalized radial amplitude of scattering.
Transverse amplitude ratio measuring the absolute transverse amplitude over the norm of radial and transverse amplitude is argued to be an indicator of small-scale surface roughness. It is mapped as an attribute on the 410-discontinuity surface manually picked from PWMIG result.
Large-scale topography of the surface is reflected on the distorted lattice. The color scale of transverse ratio is set to transparent under 0.25. Black lines are the state boundaries and coastlines mapped to a constant depth of 400 km for geo-reference.
Cartoons at upper right corner are the possible models of P to SH scattering producing the observed transverse signal: 1) a sharp interface with rough topography at a scale well smaller than the wavelength and 2) a sharp boundary overlain by interleaved sheets of variable properties that behave anisotropically. These small-scale roughness features are superimposed on the large-scale topography variation for the discontinuities.
Debi Kilb - Scripps Institution of Oceanography
Our aim is to design an automated detection scheme to catalog local earthquakes recorded by the USArray Transportable Array (USArray TA) network (points distributed throughout the continental United States), which can be used to help test the hypothesis that a large earthquake (e.g., large star, contours illustrate the mainshock’s seismic-waves trajectory where the bolder the contour the larger the seismic- wave amplitudes) can trigger small aftershocks at remote distances (i.e., small star, many mainshock fault lengths away).
These distant aftershocks are assumed to be triggered by dynamic stress changes caused by the mainshock’s seismic waves (pull-out cartoon).