Distributed acoustic sensing of microseismic sources and wave propagation in glaciated terrain

Records of Alpine microseismicity are a powerful tool to study landscape-shaping processes and warn against hazardous mass movements. Unfortunately, seismic sensor coverage in Alpine regions is typically insufficient. Here we show that distributed acoustic sensing (DAS) bridges critical observational gaps of seismogenic processes in Alpine terrain. Dynamic strain measurements in a 1 km long fiber optic cable on a glacier surface produce high-quality seismograms related to glacier flow and nearby rock falls. The nearly 500 cable channels precisely locate a series of glacier stick-slip events (within 20–40 m) and reveal seismic phases from which thickness and material properties of the glacier and its bed can be derived. As seismic measurements can be acquired with fiber optic cables that are easy to transport, install and couple to the ground, our study demonstrates the potential of DAS technology for seismic monitoring of glacier dynamics and natural hazards. In this study, Walter and colleagues deploy a 1 km long fiber optics cable on a glacier surface. Via the use of distributed acoustic sensing, the authors are capable of monitoring glacier dynamics and Alpine mass movements.

[1]  Frank Scherbaum,et al.  Evidence for deep icequakes in an Alpine glacier , 2000, Annals of Glaciology.

[2]  J. C. Savage,et al.  Icequakes on the Athabasca Glacier , 1970 .

[3]  J. Schweizer,et al.  Automatic detection of snow avalanches in continuous seismic data using hidden Markov models , 2017 .

[4]  P. Poli.  Creep and slip: Seismic precursors to the Nuugaatsiaq landslide (Greenland) , 2017 .

[5]  A. Smith.  Basal conditions on Rutford Ice Stream, West Antarctica, from seismic observations , 1997 .

[6]  Davide Calonico,et al.  Ultrastable laser interferometry for earthquake detection with terrestrial and submarine cables , 2018, Science.

[7]  Sridhar Anandakrishnan,et al.  Micro-earthquakes beneath Ice Streams Β and C, West Antarctica: observations and implications , 1993, Journal of Glaciology.

[8]  A. Helmstetter,et al.  Meltwater influences on deep stick‐slip icequakes near the base of the Greenland Ice Sheet , 2016 .

[9]  D. Macayeal,et al.  Basal friction of Ice Stream E, West Antarctica , 1995 .

[10]  N. Hovius,et al.  Seismic monitoring of small alpine rockfalls – validity, precision and limitations , 2017 .

[11]  R. Armstrong,et al.  The Physics of Glaciers , 1981 .

[12]  R. Alley,et al.  Influence of subglacial geology on the position of a West Antarctic ice stream from seismic observations , 1998, Nature.

[13]  P. Roux,et al.  Using glacier seismicity for phase velocity measurements and Green's function retrieval , 2015 .

[14]  马哈茂德·法哈蒂罗山,et al.  Method and apparatus for optical sensing of the , 2010 .

[15]  J. Ajo-Franklin,et al.  Introduction to Interferometry of Fiber Optic Strain Measurements , 2018 .

[16]  A. Maurel,et al.  Propagation of elastic waves through textured polycrystals: application to ice , 2015, Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[17]  N. Hovius,et al.  Seismic monitoring of torrential and fluvial processes , 2016 .

[18]  E. Papadimitriou,et al.  3D crustal structure from local earthquake tomography around the Gulf of Arta (Ionian region, NW Greece) , 1999 .

[19]  J. Walter,et al.  Subseasonal changes observed in subglacial channel pressure, size, and sediment transport , 2016 .

[20]  F. Walter,et al.  Seasonal variations of glacier seismicity at the tongue of Rhonegletscher (Switzerland) with a focus on basal icequakes , 2016, Journal of Glaciology.

[21]  Agnès Helmstetter,et al.  Location of Seismic Signals Associated with Microearthquakes and Rockfalls on the Séchilienne Landslide, French Alps , 2011 .

[22]  A. Bauder,et al.  Helicopter-borne ground-penetrating radar investigations on temperate alpine glaciers: A comparison of different systems and their abilities for bedrock mapping , 2016 .

[23]  G. Laske,et al.  Crevasse-induced Rayleigh-wave azimuthal anisotropy on Glacier de la Plaine Morte, Switzerland , 2018, Annals of Glaciology.

[24]  Jean Virieux,et al.  Probabilistic Earthquake Location in 3D and Layered Models , 2000 .

[25]  Tom Richard Parker,et al.  Distributed Acoustic Sensing – a new tool for seismic applications , 2014 .

[26]  L. Rabenstein,et al.  Detecting and characterising an englacial conduit network within a temperate Swiss glacier using active seismic, ground penetrating radar and borehole analysis , 2019, Annals of Glaciology.

[27]  Donat Fäh,et al.  Automatic detection of avalanches using a combined array classification and localization , 2018 .

[28]  Eileen R. Martin,et al.  A Seismic Shift in Scalable Acquisition Demands New Processing: Fiber-Optic Seismic Signal Retrieval in Urban Areas with Unsupervised Learning for Coherent Noise Removal , 2018, IEEE Signal Processing Magazine.

[29]  Inder Monga,et al.  Distributed Acoustic Sensing Using Dark Fiber for Near-Surface Characterization and Broadband Seismic Event Detection , 2019, Scientific Reports.

[30]  D. Farinotti,et al.  Investigating the dynamics of an Alpine glacier using probabilistic icequake locations: Triftgletscher, Switzerland , 2013 .

[31]  J. Schweizer,et al.  Forecasting snow avalanches using avalanche activity data obtained through seismic monitoring , 2016 .

[32]  K. Allstadt,et al.  Seismic and acoustic signatures of surficial mass movements at volcanoes , 2018, Journal of Volcanology and Geothermal Research.

[33]  Michel Jaboyedoff,et al.  Ambient seismic noise monitoring of a clay landslide: Toward failure prediction , 2012 .

[34]  D. Or,et al.  Speed and attenuation of acoustic waves in snow: laboratory experiments and modeling with Biot's theory , 2016 .

[35]  T. Daley,et al.  Field testing of modular borehole monitoring with simultaneous distributed acoustic sensing and geophone vertical seismic profiles at Citronelle, Alabama , 2016 .

[36]  L. Baillet,et al.  Environmental seismology: What can we learn on earth surface processes with ambient noise? , 2015 .

[37]  Martin Funk,et al.  Basal icequakes during changing subglacial water pressures beneath Gornergletscher, Switzerland , 2008, Journal of Glaciology.

[38]  Laurent Baillet,et al.  Analysis of seismic signals recorded on a prone-to-fall rock column (Vercors massif, French Alps) , 2011 .

[39]  Gary F. Margrave.  New seismic modelling facilities in Matlab , 2000 .

[40]  R. Alley,et al.  Till beneath ice stream B: 1. Properties derived from seismic travel times , 1987 .

[41]  Patrick Paitz,et al.  Rotation and strain ambient noise interferometry , 2019, Geophysical Journal International.

[42]  R. Aster,et al.  Glacial seismology , 2017, Reports on progress in physics. Physical Society.

[43]  P. Jousset,et al.  Dynamic strain determination using fibre-optic cables allows imaging of seismological and structural features , 2018, Nature Communications.

[44]  F. Walter,et al.  Crack wave resonances within the basal water layer , 2019, Annals of Glaciology.

[45]  F. Walter,et al.  High‐Frequency (>2 Hz) Ambient Seismic Noise on High‐Melt Glaciers: Green's Function Estimation and Source Characterization , 2018, Journal of Geophysical Research: Earth Surface.

[46]  M. Lüthi,et al.  Caterpillar‐like ice motion in the ablation zone of the Greenland ice sheet , 2014 .

[47]  Pierre Comon,et al.  Basal icequakes recorded beneath an Alpine glacier (Glacier d'Argentière, Mont Blanc, France): Evidence for stick‐slip motion? , 2015 .

[48]  Eileen R. Martin,et al.  Fiber‐Optic Network Observations of Earthquake Wavefields , 2017 .

[49]  Gaël Durand,et al.  Potential sea-level rise from Antarctic ice-sheet instability constrained by observations , 2015, Nature.