Seismic Network in Greenland Monitors Earth and Ice System

Clinton, John; Nettles, M.; Walter, Fabian; Anderson, Kent; Dahl‐Jensen, Trine; Giardini, Domenico; Govoni, Aladino; Hanka, W.; Lasocki, Stanisław; Lee, Won Sang; McCormack, D.; Mykkeltveit, Svein; Stutzmann, É.; Tsuboi, Seiji

doi:10.1002/2014eo020001

Cited by 47 publications

(30 citation statements)

References 6 publications

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“…The triangles outlined in blue represent the additional stations used for ambient noise tomography. The stations are part of the Greenland Ice Sheet Monitoring Network (Clinton et al, 2014), and the XF (Nettles, 2014), X5 (Hudson Bay Lithospheric Experiment; Bastow et al, 2013), or 1E (Ellesmere Island Lithosphere Experiment; Stephenson et al, 2013) networks. The topography information is from ETOPO1 (Amante & Eakins, 2009). pairs.…”

Section: Ambient Noise Tomographymentioning

confidence: 99%

Lithospheric Structure of Greenland From Ambient Noise and Earthquake Surface Wave Tomography

Pourpoint¹,

Anandakrishnan

Ammon

et al. 2018

JGR Solid Earth

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We present a high‐resolution shear wave velocity model of Greenland's lithosphere from regional and teleseismic Rayleigh waves recorded by the Greenland Ice Sheet Monitoring Network supplemented with observations from several temporary seismic deployments. To construct Rayleigh wave group velocity maps, we integrated signals from regional and teleseismic earthquakes with several years of ambient seismic noise and used the dispersion to constrain crustal and upper‐mantle seismic shear wave velocity structure. Specifically, we used a Markov Chain Monte Carlo technique to estimate 3‐D shear wave velocities beneath Greenland to a depth of 200 km. Our model reveals four prominent anomalies: a deep high‐velocity feature extending from southwestern to northwestern Greenland that may be the signature of a thick cratonic keel, a corridor of relatively low upper‐mantle velocity across central Greenland that could be associated with lithospheric modification from the passage of the Iceland plume beneath Greenland or interpreted as a tectonic boundary between cratonic blocks, an upper‐crustal southwest‐northeast trending boundary separating Greenland into two regions of contrasting tectonic and crustal properties, and a midcrustal low‐velocity anomaly beneath northeastern Greenland. The nature of this midcrustal anomaly is of particular interest given that it underlies the onset of the Northeast Greenland Ice Stream and raises interesting questions regarding how deeper processes may impact the ice stream dynamics and the evolution of the Greenland Ice Sheet.

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Section: Ambient Noise Tomographymentioning

confidence: 99%

Lithospheric Structure of Greenland From Ambient Noise and Earthquake Surface Wave Tomography

Pourpoint¹,

Anandakrishnan

Ammon

et al. 2018

JGR Solid Earth

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“…It was recorded by broadband seismic stations located in Greenland. We use seismic records from four permanent stations of the GLISN network [ Clinton et al , ], ILULI, SFJD, SUMG, and KULLO, located, respectively, 57, 247, 556, and 661 km from the calving zone (Figure a). We also use data from a broadband station (WIND) which was temporally installed on the bedrock 4 km from the source area.…”

Section: Description Of the Calving Event And Seismic Datamentioning

confidence: 99%

Complex force history of a calving‐generated glacial earthquake derived from broadband seismic inversion

Sergeant

Mangeney

Stutzmann

et al. 2016

Geophysical Research Letters

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The force applied to the Earth by the calving of two icebergs at Jakobshavn Isbrae, Greenland, has been quantified. The source force history was recovered by inversion of regional broadband seismograms without any a priori constraint on the source time function, in contrast with previous studies. For periods 10–100 s, the three‐component force can be obtained from distant stations alone and is proportional to the closest station seismograms. This inversion makes it possible to quantify changes of the source force direction and amplitude as a function of time and frequency. A detailed comparison with a video of the event was used to identify four forces associated with collision, then bottom‐out and top‐out rotation of the first and second icebergs, and ice mélange motion. Only the two iceberg rotations were identified in previous studies. All four processes are found here to contribute to the force amplitude and variability. Such a complete time‐frequency force history provides unique dynamical constraints for mechanical calving models.

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“…For the interpretation, we have further included data from four stations (DBG, ICESG, SCO, SUMG) of the GLISN network (Clinton et al, 2014) and HJO of the GLATIS project ; Table 1 and Figure 2).…”

Section: Data Setmentioning

confidence: 99%

Crustal Structure in Central‐Eastern Greenland From Receiver Functions

et al. 2019

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The crustal structure in the interior of Greenland is largely unknown because of its remote location below the up to 3.4‐km‐thick ice sheet. We present a model of the crustal velocity structure in central‐eastern Greenland based on simultaneous inversion of P and S receiver functions for data acquired at 23 broadband stations between the coast and the center of the ice sheet. The area is believed to mainly include Precambrian basement and includes a part covered by Tertiary volcanic rocks and some sedimentary basins. Our results show a westward deepening Moho from less than 20 km at the coast to 50 km below central Greenland. Crustal S wave velocities are generally 3.75 km/s through the whole crust which may be relatively small for Precambrian areas, and Vp/Vs is generally around 1.73, although slightly higher in central Greenland. In the coastal area we observe anomalously low velocities at the top of the crust. In the volcanic area south of Scoresbysund Fjord this layer has very high Vp/Vs (>2), which indicates a high mafic content and the presence of water‐filled cracks in the basaltic material. In the north, outside the volcanic area, Vp/Vs is normal and the low‐velocity layer probably is instead related to the presence of sedimentary basins. At stations in the center of our study area we find low Vs and high Vp/Vs in the lower crust. Based on the Moho topography, our results do not support Airy type isostasy as explanation of the high topography in eastern Greenland.

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Seismic Network in Greenland Monitors Earth and Ice System

Cited by 47 publications

References 6 publications

Lithospheric Structure of Greenland From Ambient Noise and Earthquake Surface Wave Tomography

Lithospheric Structure of Greenland From Ambient Noise and Earthquake Surface Wave Tomography

Complex force history of a calving‐generated glacial earthquake derived from broadband seismic inversion

Crustal Structure in Central‐Eastern Greenland From Receiver Functions

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