<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Carr, Chris G.</style></author><author><style face="normal" font="default" size="100%">Carmichael, Joshua D.</style></author><author><style face="normal" font="default" size="100%">Pettit, Erin C.</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Wintertime brine discharge at the surface of a cold polar glacier and the unexpected absence of associated seismicity</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Geophysical Research: Earth Surface</style></secondary-title><short-title><style face="normal" font="default" size="100%">JGR Earth Surface</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">crevasses</style></keyword><keyword><style  face="normal" font="default" size="100%">cryoseismology</style></keyword><keyword><style  face="normal" font="default" size="100%">glacier hydrology</style></keyword><keyword><style  face="normal" font="default" size="100%">Rayleigh waves</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2022</style></year><pub-dates><date><style  face="normal" font="default" size="100%">03/2022</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://onlinelibrary.wiley.com/doi/10.1029/2021JF006325</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">127</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;A subglacial groundwater system beneath Taylor Glacier, Antarctica, discharges hypersaline, iron-rich brine episodically at the glacier surface to create Blood Falls. However, the triggering mechanism for these brine release events is not yet understood. Identifying which fracture processes are observed seismically can help us better characterize the hydrological system at Taylor Glacier, and more generally, provide us with a broader understanding of englacial hydrologic activity in cold glaciers. We document wintertime brine discharge using time-lapse photography. Subfreezing air temperatures during the brine discharge indicate that surface melt-induced hydrofracture is an unlikely trigger for brine release. Further, we analyze local seismic data to test a hypothesis that fracturing generates elevated surface wave energy preceding and/or coinciding with brine release events. Our results show no discernible elevated Rayleigh wave activity prior to or during Blood Falls brine release. Instead, we find a pattern of seismic events dominated by a seasonal signal, with more Rayleigh events occurring in the summer than the winter from the Blood Falls source area. We calculate that the volumetric opening of cracks that would generate Rayleigh waves at our detection limits are of similar size to myriad cracks in glacier ice, lake ice, and frozen sediment in the terminus area. We therefore propose that any fracturing coincident with brine release activity likely consists of a series of smaller opening events that are masked by other seismicity in the local environment.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Carr, Chris G.</style></author><author><style face="normal" font="default" size="100%">Carmichael, J. D.</style></author><author><style face="normal" font="default" size="100%">Pettit, Erin C.</style></author><author><style face="normal" font="default" size="100%">Truffer, Martin</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The influence of environmental microseismicity on detection and interpretation of small-magnitude events in a polar glacier setting</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Glaciology</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2020</style></year><pub-dates><date><style  face="normal" font="default" size="100%">07/2020</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://www.cambridge.org/core/journals/journal-of-glaciology/article/influence-of-environmental-microseismicity-on-detection-and-interpretation-of-smallmagnitude-events-in-a-polar-glacier-setting/E1A441425341F677117509351F3C6763</style></url></web-urls></urls><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Glacial environments exhibit temporally variable microseismicity. To investigate how microseismicity influences event detection, we implement two noise-adaptive digital power detectors to process seismic data from Taylor Glacier, Antarctica. We add scaled icequake waveforms to the original data stream, run detectors on the hybrid data stream to estimate reliable detection magnitudes and compare analytical magnitudes predicted from an ice crack source model. We find that detection capability is influenced by environmental microseismicity for seismic events with source size comparable to thermal penetration depths. When event counts and minimum detectable event sizes change in the same direction (i.e. increase in event counts and minimum detectable event size), we interpret measured seismicity changes as &amp;lsquo;true&amp;rsquo; seismicity changes rather than as changes in detection. Generally, one detector (two degree of freedom (2dof)) outperforms the other: it identifies more events, a more prominent summertime diurnal signal and maintains a higher detection capability. We conclude that real physical processes are responsible for the summertime diurnal inter-detector difference. One detector (3dof) identifies this process as environmental microseismicity; the other detector (2dof) identifies it as elevated waveform activity. Our analysis provides an example for minimizing detection biases and estimating source sizes when interpreting temporal seismicity patterns to better infer glacial seismogenic processes.&lt;/p&gt;</style></abstract></record></records></xml>