Skip to main content Accessibility help
×
Home

Seismic detection of transient changes beneath Black Rapids Glacier, Alaska, U.S.A.: I. Techniques and observations

  • Matt Nolan (a1) and Keith Echelmeyer (a1)

Abstract

To gain new insight into the mechanisms of basal motion, we have demonstrated the feasibility of an active seismic technique to measure temporal changes in basal conditions on sub-hourly time-scales. One region of the bed of Black Rapids Glacier, Alaska, U.S.A., was monitored for a period of 45 days using seismic reflections. The majority of these reflections were nearly identical. However, three significant anomalies were recorded several days apart. These corresponded with the englacial drainage of two ice-marginal lakes and one supraglacial pothole, each up-glacier of the study site, as well as dramatic increases in basal motion. Two of these seismic anomalies revealed identical changes over 1 km2 of the bed despite the fact that their drainage events occurred at different locations. Further, these two seismic anomalies were followed by records identical to the non-anomalous state, showing that the seismic changes were reversible. In one of these events, two records taken 36 min apart revealed that the transition between the anomalous and normal states occurred completely within this short interval.

  • View HTML
    • Send article to Kindle

      To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle.

      Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

      Find out more about the Kindle Personal Document Service.

      Seismic detection of transient changes beneath Black Rapids Glacier, Alaska, U.S.A.: I. Techniques and observations
      Available formats
      ×

      Send article to Dropbox

      To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Dropbox.

      Seismic detection of transient changes beneath Black Rapids Glacier, Alaska, U.S.A.: I. Techniques and observations
      Available formats
      ×

      Send article to Google Drive

      To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your <service> account. Find out more about sending content to Google Drive.

      Seismic detection of transient changes beneath Black Rapids Glacier, Alaska, U.S.A.: I. Techniques and observations
      Available formats
      ×

Copyright

References

Hide All
Anandakrishnan, S. and Alley, R. B.. 1997. Tidal forcing of basal seismicity of Ice Stream C, West Antarctica, observed far inland. J. Geophys. Res., 102(B7), 15,183–15,196.
Atre, S. R. and Bentley, C. R.. 1993. Laterally varying basal conditions beneath Ice Streams B and C, West Antarctica. J. Glaciol., 39 (133), 507514.
Bentley, C. R. 1971. Seismic evidence for moraine within the basal Antarctic ice sheet. In Crary, A. P., ed. Antarctic snow and ice studies II. Washington, DC, American Geophysical Union, 89–129. (Antarctic Research Series 16.)
Blankenship, D. D., Bentley, C. R., Rooney, S. T. and Alley, R. B.. 1987. Till beneath Ice Stream B. I. Properties derived from seismic travel times. J. Geophys. Res., 92 (B9), 89038911.
Clarke, T. S. 1991. Glacier dynamics in the Susitna River basin, Alaska, U.S.A. J. Glaciol., 37 (125), 97106.
Clarke, T. S. and Echelmeyer, K.. 1996. Seismic-reflection evidence for a deep subglacial trough beneath Jakobshavns Isbræ, West Greenland. J. Glaciol., 42 (141), 219232.
Cochran, O. D., 1995. The subglacial hydraulics of the surge-type Black Rapids Glacier, Alaska: a schematic model. (M.Sc. thesis, University of Alaska Fairbanks.)
Gades, A. M. 1998. Spatial and temporal variations of basal conditions beneath glaciers and ice sheets inferred from radio echo soundings. (Ph.D. thesis, University of Washington.)
Hance, J. H. 1937. The recent advance of Black Rapids Glacier, Alaska. J. Geol., 45, 775783.
Harrison, W. D., Mayo, L. R. and Trabant, D. C.. 1975. Temperature measurements on Black Rapids Glacier, Alaska, 1973. In Weller, G. and Bowling, S. A., eds. Climate of the Arctic. Fairbanks, AK, University of Alaska Geophysical Institute, 350352.
Harrison, W. D., Echelmeyer, K. A., Chacho, E. F., Raymond, C. F. and Benedict, R. J.. 1994. The 1987–88 surge of West Fork Glacier, Susitna Basin, Alaska, U.S.A. J. Glaciol., 40 (135), 241254.
Heinrichs, T. A., Mayo, L. R., Echelmeyer, K. A. and Harrison, W. D.. 1996. Quiescent-phase evolution of a surge-type glacier: Black Rapids Glacier, Alaska, U.S.A. J. Glaciol., 42 (140), 110122.
Kamb, B. and 7 others. 1985. Glacier surge mechanism: 1982–1983 surge of Variegated Glacier. Alaska. Science, 227 (4686), 469479.
Mavko, G. and Nur, A.. 1975. Melt squirt in the asthenosphere. J. Geophys. Res., 80 (11), 14441448.
Nokleberg, W. J. and 6 others. 1992. Preliminary geologic map of the Mount Haves quadrangle, eastern Alaska Range. Alaska. U.S. Geol. Surv. Open File Rep. 92594, Scale 1:250 000.
Nolan, M. 1997. Seismic detection of transient subglacial changes beneath Black Rapids Glacier, Alaska. (Ph.D. thesis, University of Alaska Fairbanks.)
Nolan, M. and Echelmeyer, K.. 1999. Seismic detection of transient changes beneath Black Rapids Glacier. Alaska, U.S.A.: II. Basal morphology and processes. J. Glaciol., 45 (149), 132146.
Nolan, M., Motyka, R. J., Echelmeyer, K. and Trabant, D. C.. 1995. Ice-thickness measurements of Taku Glacier, Alaska, U.S.A., and their relevance to its recent behavior. J. Glaciol., 41 (139), 541553.
Paterson, W. S. B. 1994. The physics of glaciers. Third edition. Oxford, etc., Elsevier.
Raymond, C. F. and Malone, S.. 1986. Propagating strain anomalies during mini-surges of Variegated Glacier, Alaska, U.S.A. J. Glaciol., 32 (111), 178191.
Raymond, C. F., Benedict, R. J., Harrison, W. D., Echelmeyer, K. A. and Sturm, M.. 1995. Hydrological discharges and motion of Fels and Black Rapids Glaciers, Alaska, U.S.A.: implications for the structure of their drainage systems. J. Glaciol., 41 (138), 290304.
Reger, R. D., Sturmann, A. G. and Beget, J. E.. 1993. Dating Holecene moraines of Black Rapids Glacier, Delta River valley, central Alaska Range. In Solie, D. N. and Tannian, F., eds. Short notes on Alaskan geology 1993. Fairbanks, AK, Alaska Division of Geological and Geophysical Surveys, 5159. (Professional Report 113.)
Richards, M. A. 1988. Seismic evidence for a weak basal layer during the 1982 surge of Variegated Glacier, Alaska, U.S.A. J. Glaciol., 34 (116), 111120.
Rooney, S. T., Blankenship, D. D., Alley, R. B. and Bentley, C. R.. 1987. Till beneath Ice Stream B. 2. Structure and continuity. J. Geophys. Res., 92 (B9), 89138920.
Röthlisberger, H. 1972. Seismic exploration In cold regions. I. CRREL Monogr. II-A2a.
Sheriff, R. E. and Geldart, L. P.. 1995. Exploration seismology. Cambridge, Cambridge University Press.
Smith, A. M. 1997. Basal conditions on Rutford Ice Stream, West Antarctica from seismic observations. J. Geophys. Res., 102 (B1), 543552.
Sturm, M. and Cosgrove, D. M.. 1990. Correspondence. An unusual jökulhlaup involving potholes on Black Rapids Glacier, Alaska Range, Alaska, U.S.A. J. Glaciol., 36 (122), 125126.
Truffer, M., Harrison, W. D., Echelmeyer, K. A., J. Gorda-DeMaillie and Heinrichs, T. A.. 1996. Velocity variations of surge type Black Rapids Glacier. [Abstract.] EOS, 77 (46), Fall Meeting Supplement, F213.
Wolf, L. W. and Davies, J. N.. 1986. Glacier-generated earthquakes from Prince William Sound, Alaska. Bull. Seismol. Soc. Am., 76 (2), 367379.

Metrics

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed