Skip to main content Accessibility help
×
Home

Effects of ash layers of the 2004 Grímsvötn eruption on SAR backscatter in the accumulation area of Vatnajökull

  • K. Scharrer (a1), C. Mayer (a2), T. Nagler (a3), U. Münzer (a1) and Á. Guðmundsson (a4)...

Abstract

The applicability of volcanic ash deposits on Vatnajökull ice cap, Iceland, as a time reference marker for measuring accumulation by the analysis of time sequential SAR backscatter data was investigated. A volcanic eruption at Grímsvötn caldera, a subglacial volcanic system beneath Vatnajökull, deposited an ash layer north of the vent in early November 2004. This ash layer covered a V-shaped area of ∽88km2 on the glacier surface. The ash fall, which was subsequently buried by snow, reveals a distinct backscatter signal in SAR images. In total, the σ 0 backscatter values of 40 ENVISAT-ASAR images were analyzed, covering two post-eruption accumulation periods (4 November 2004 to 31 March 2005 and 25 October 2006 to 14 March 2006). Significant differences over time were observed in the SAR backscatter signals over the deposited ash, which appear to be related to the snow accumulation history. The backscatter signals were compared to meteorological conditions at the time of SAR acquisition and to accumulation data derived from two snow pits, one located within the ash fall. A linear regression analysis between the accumulation data and the SAR backscattering coefficient results in high R2 confidence values (>0.8), indicating that the SAR data can be used for estimating the areal accumulation distribution in areas with an existing ash layer.

  • 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.

      Effects of ash layers of the 2004 Grímsvötn eruption on SAR backscatter in the accumulation area of Vatnajökull
      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.

      Effects of ash layers of the 2004 Grímsvötn eruption on SAR backscatter in the accumulation area of Vatnajökull
      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.

      Effects of ash layers of the 2004 Grímsvötn eruption on SAR backscatter in the accumulation area of Vatnajökull
      Available formats
      ×

Copyright

References

Hide All
Adalgeirsdóttir, G. 2003. Flow dynamics of Vatnajökull ice cap, Iceland. (PhD thesis, ETH-VAW Zürich.)
Björnsson, H. 1978. The surface area of glaciers in Iceland. Jökull, 28, 31.
Björnsson, H. and Einarsson, P.. 1990. Volcanoes beneath Vatnaj ökull, Iceland: evidence from radio echo-sounding, earthquakes and jökulhlaups. Jökull, 40, 147–168.
Björnsson, H., Palsson, F., Adalgeirsdöttir, G. and Guðmundsson, S.. 2005. Mass balance of Vatnajökull (1991–2004) and Langjökull (1996–2004) ice caps, Iceland. Geoph. Res. Abs., 7, 06485.
Guðmundsson, M.T. and Björnsson, H.. 1993. Eruptions in Grímsvötn, Vatnajökull Iceland 1934–1991. Jökull, 41, 21–45.
Hardardóttir, J., Jonsson, P., Sigurdsson, G., Elefsen, S.O., Sigfusson, B. and Gislason, S.. 2005. Discharge and sediment monitoring of the 2004 glacial outburst flood event (jökulhlaup) on Skeidara sandur plain south Iceland. Geoph. Res. Abs., 7, 08854.
Henderson, F.M. and Lewis, A.J., eds. 1998. Manual of remote sensing: principles and application of imaging radar. Third edition. New York, NY, John Wiley & Sons.
Lopes, A., Ridha, T. and Nezry, E.. 1990. Adaptive filters and scene heterogeneity. IEEE Trans. Geosci. Remote Sens., 28(6), 992–1000.
Rosich, B. and Meadows, P.. 2004. Absolute calibration of ASAR level 1 products generated with PF-ASAR. ESA-ESRIN Technical Note, ENVI-CLVL-EOPG-TN-03-0010.
Sigmundsson, F. and Guðmundsson, M.T.. 2004. Eldgosið ĺ Grímsvötnum í nóvember 2004 – the Grímsvötnum eruption, November 2004. Jökull, 54, 139–143.

Effects of ash layers of the 2004 Grímsvötn eruption on SAR backscatter in the accumulation area of Vatnajökull

  • K. Scharrer (a1), C. Mayer (a2), T. Nagler (a3), U. Münzer (a1) and Á. Guðmundsson (a4)...

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