USAP-DC

Bromirski/1246151 This award supports a project intended to discover, through field observations and numerical simulations, how ocean wave-induced vibrations on ice shelves in general, and the Ross Ice Shelf (RIS), in particular, can be used (1) to infer spatial and temporal variability of ice shelf mechanical properties, (2) to infer bulk elastic properties from signal propagation characteristics, and (3) to determine whether the RIS response to infragravity (IG) wave forcing observed distant from the front propagates as stress waves from the front or is "locally" generated by IG wave energy penetrating the RIS cavity. The intellectual merit of the work is that ocean gravity waves are dynamic elements of the global ocean environment, affected by ocean warming and changes in ocean and atmospheric circulation patterns. Their evolution may thus drive changes in ice-shelf stability by both mechanical interactions, and potentially increased basal melting, which in turn feed back on sea level rise. Gravity wave-induced signal propagation across ice shelves depends on ice shelf and sub-shelf water cavity geometry (e.g. structure, thickness, crevasse density and orientation), as well as ice shelf physical properties. Emphasis will be placed on observation and modeling of the RIS response to IG wave forcing at periods from 75 to 300 s. Because IG waves are not appreciably damped by sea ice, seasonal monitoring will give insights into the year-round RIS response to this oceanographic forcing. The 3-year project will involve a 24-month period of continuous data collection spanning two annual cycles on the RIS. RIS ice-front array coverage overlaps with a synergistic Ross Sea Mantle Structure (RSMS) study, giving an expanded array beneficial for IG wave localization. The ice-shelf deployment will consist of sixteen stations equipped with broadband seismometers and barometers. Three seismic stations near the RIS front will provide reference response/forcing functions, and measure the variability of the response across the front. A linear seismic array orthogonal to the front will consist of three stations in-line with three RSMS stations. Passive seismic array monitoring will be used to determine the spatial and temporal distribution of ocean wave-induced signal sources along the front of the RIS and estimate ice shelf structure, with the high-density array used to monitor and localize fracture (icequake) activity. The broader impacts include providing baseline measurements to enable detection of ice-shelf changes over coming decades which will help scientists and policy-makers respond to the socio-environmental challenges of climate change and sea-level rise. A postdoctoral scholar in interdisciplinary Earth science will be involved throughout the course of the research. Students at Cuyamaca Community College, San Diego County, will develop and manage a web site for the project to be used as a teaching tool for earth science and oceanography classes, with development of an associated web site on waves for middle school students.

Person	Role
Bromirski, Peter	Investigator and contact
Gerstoft, Peter	Co-Investigator
Stephen, Ralph	Investigator

Antarctic Glaciology	Award # 1246416
Antarctic Glaciology	Award # 1246151

USAP-1246151_1

Deployment	Type
Ross Ice Shelf	field camp

None in the Database

Repository	Title (link)	Format(s)	Status
IRIS	Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-Induced Vibrations and Collaborative Research: Mantle Structure and Dynamics of the Ross Sea from a Passive Seismic Deployment on the Ross Ice Shelf. International Federation of Digital Seismograph Networks.	Not Provided	exists
UNAVCO	Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations 2015/2016, UNAVCO, Inc., GPS/GNSS Observations Dataset	Not Provided	exist

1. Baker, M.G., Aster, R.C., Wiens, D.A., Nyblade, A., Bromirski, P.D., Gerstoft, P., Stephen, R.A. (2020). Teleseismic earthquake wavefields observed on the Ross Ice Shelf, J. Glaciol. (doi:10.1017/jog.2020.83)
2. Klein, E., C. Mosbeux, P.D. Bromirski, L. Padman, Y. Bock, S.R. Springer, and H.A. Fricker (2020). Annual cycle in flow of Ross Ice Shelf, Antarctica: contribution of variable basal melting, J. Glaciol., 1-15 (doi:10.1017/jog.2020.61)
3. Chen, Z., P.D. Bromirski, P. Gerstoft, R.A. Stephen, W.S. Lee, S. Yun, S.D. Olinger, D.A., Wiens, R.C. Aster, and A. Nyblade (2019). Ross Ice Shelf icequakes associated with ocean gravity wave activity, Geophys. Res. Lett, 46 (doi:10.1029/2019GL084123)
4. Baker, M.G., Aster, R.C., Anthony, R., Chaput, J., Wiens, D., Nyblade, A., Bromirski, P.D., Stephen, R., Gerstoft, P. (2019). Seasonal and spatial variations in the ocean-coupled ambient wavefield of the Ross Ice Shelf, Annals of Glaciology (doi:10.1029/2019GL082842)
5. Chaput, J., Aster, R.C., McGrath, D., Baker, M., Anthony, R.E., Gerstoft, P., Bromirski, P.D., Nyblade, A., Stephen, R.A., Wiens, D. (2018). Near-surface wind, temperature, and melt-induced changes on the Ross Ice Shelf observed continuously with seismology, Geophys. Res. Lett. (doi:10.1029/2018GL079665)
6. Chen, Z., P.D. Bromirski, P. Gerstoft, R.A. Stephen, D.A. Wiens, R.C. Aster, and A. Nyblade (2018). Ocean-excited plate waves in the Ross and Pine Island Glacier Ice Shelves, J. Glaciol (doi:10.1017/jog.2018.66)
7. Bromirski, P.D., Z. Chen, R.A. Stephen, P. Gerstoft, D. Arcas, A. Diez, R.C. Aster, D.A. Wiens, and A. Nyblade (2017). Tsunami and infragravity waves impacting Antarctic ice shelves, J. Geophys. Res.-Oceans (doi:10.1002/2017JC012913)
8. Diez, A., P.D. Bromirski, P. Gerstoft, R.A. Stephen, R.E. Anthony, R.C. Aster, C. Cai, A. Nyblade, and D.A. Wiens (2016). Ice shelf structure derived from dispersion curve analysis of ambient seismic noise, Geophys. J. Int., 205, 785-795 (doi:10.1093/gji/ggw036)
9. Bromirski, P.D., A. Diez, P. Gerstoft, R.A. Stephen, T. Bolmer, D.A. Wiens, R.C. Aster, and A. Nyblade (2015). Ross ice shelf vibrations, Geophys. Res. Lett., 42 (doi:10.1002/2015GL065284)
10. White-Gaynor, A., Nyblade, A., Aster, R.C., Wiens, D., Bromirski, P., Gerstoft, P., Stephen, R., Hansen, S., Wilson, T., Dalziel, I. Huerta, A., Winberry, P., Anandakrishnan, S., Heterogeneous upper mantle structure beneath the Ross Sea Embayment and Marie Byrd Land, West Antarctica, revealed by P-wave tomography, EPSL, 513, 40 - 50, 2019. (doi:10.1016/j.epsl.2019.02.013)
11. Lucas, E. M., Nyblade, A. A., Accardo, N. J., Lloyd, A. J., Wiens, D. A., Aster, R. C., Wilson, T. J., Dalziel, I. W., Stuart, G. W., O’Donnell, J. P., Winberry, J. P., & Huerta, A. D. (2022). Shear Wave Splitting Across Antarctica: Implications for Upper Mantle Seismic Anisotropy. Journal of Geophysical Research: Solid Earth, 127(4). Portico. (doi:10.1029/2021jb023325)
12. Booth, A. D., Emir, E., & Diez, A. (2016). Approximations to seismic AVA responses: Validity and potential in glaciological applications. GEOPHYSICS, 81(1), WA1–WA11. (doi:10.1190/geo2015-0187.1)
13. Chen, Z., Bromirski, P. D., Gerstoft, P., Stephen, R. A., Lee, W. S., Yun, S., … Nyblade, A. A. (2019). Ross Ice Shelf Icequakes Associated With Ocean Gravity Wave Activity. Geophysical Research Letters, 46(15), 8893–8902. (doi:10.1029/2019gl084123)
14. Shen, W., Wiens, D. A., Anandakrishnan, S., Aster, R. C., Gerstoft, P., Bromirski, P. D., … Winberry, J. P. (2018). The Crust and Upper Mantle Structure of Central and West Antarctica From Bayesian Inversion of Rayleigh Wave and Receiver Functions. Journal of Geophysical Research: Solid Earth, 123(9), 7824–7849. (doi:10.1029/2017jb015346)
15. Olinger, S. D., Lipovsky, B. P., Wiens, D. A., Aster, R. C., Bromirski, P. D., Chen, Z., … Stephen, R. A. (2019). Tidal and Thermal Stresses Drive Seismicity Along a Major Ross Ice Shelf Rift. Geophysical Research Letters, 46(12), 6644–6652. (doi:10.1029/2019gl082842)
16. Sergienko, O. V. (2017). Behavior of flexural gravity waves on ice shelves: Application to the Ross Ice Shelf. Journal of Geophysical Research: Oceans, 122(8), 6147–6164. (doi:10.1002/2017jc012947)
17. Lucas, E. M., Soto, D., Nyblade, A. A., Lloyd, A. J., Aster, R. C., Wiens, D. A., … Huerta, A. D. (2020). P- and S-wave velocity structure of central West Antarctica: Implications for the tectonic evolution of the West Antarctic Rift System. Earth and Planetary Science Letters, 546, 116437. (doi:10.1016/j.epsl.2020.116437)
18. Hell, M. C., Cornelle, B. D., Gille, S. T., Miller, A. J., & Bromirski, P. D. (2019). Identifying Ocean Swell Generation Events from Ross Ice Shelf Seismic Data. Journal of Atmospheric and Oceanic Technology, 36(11), 2171–2189. (doi:10.1175/jtech-d-19-0093.1)
19. Bromirski, P. D., Chen, Z., Stephen, R. A., Gerstoft, P., Arcas, D., Diez, A., … Nyblade, A. (2017). Tsunami and infragravity waves impacting Antarctic ice shelves. Journal of Geophysical Research: Oceans, 122(7), 5786–5801. (doi:10.1002/2017jc012913)
20. Jenkins, W. F., Gerstoft, P., Bianco, M. J., & Bromirski, P. D. (2021). Unsupervised Deep Clustering of Seismic Data: Monitoring the Ross Ice Shelf, Antarctica. Journal of Geophysical Research: Solid Earth, 126(9). (doi:10.1029/2021jb021716)
21. Lucas, E. M., Nyblade, A. A., Aster, R. C., Wiens, D. A., Wilson, T. J., Winberry, J. P., & Huerta, A. D. (2023). Tidally Modulated Glacial Seismicity at the Foundation Ice Stream, West Antarctica. Journal of Geophysical Research: Earth Surface, 128(7). Portico. (doi:10.1029/2023jf007172)
22. Wiens, D. A., Aster, R. C., Nyblade, A. A., Bromirski, P. D., Gerstoft, P., & Stephen, R. A. (2024). Ross Ice Shelf Displacement and Elastic Plate Waves Induced by Whillans Ice Stream Slip Events. Geophysical Research Letters, 51(7). Portico. (doi:10.1029/2023gl108040)