1 / 33

Mouse Marie Larson CIDER program July 2006

Imaging the 410 and 660km discontinuities beneath the Transantarctic Mountains and the East Antarctic Craton using Receiver Functions. Mouse Marie Larson CIDER program July 2006. Talk outline. What? How? Results? Weird Results?!? What does it mean?.

finnea
Download Presentation

Mouse Marie Larson CIDER program July 2006

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Imaging the 410 and 660km discontinuities beneath the Transantarctic Mountains and the East Antarctic Craton using Receiver Functions Mouse Marie Larson CIDER program July 2006

  2. Talk outline What? How? Results? Weird Results?!? What does it mean?

  3. This study will use receiver functions to place depth constraints on any thermal anomaly beneath the TAMs Two main questions are addressed here: 1. Can receiver functions be used in Antarctica, or do the ice sheets mask arrivals from the 410 and 660 km discontinuities? 2. Is there evidence for thinning of the transition zone between the 410 and 660? http://home.freeuk.com/gtlloyd/tam/main.htm

  4. East and West Antarctica are geologically distinct http://home.freeuk.com/gtlloyd/tam/main.htm

  5. Many different mechanisms have been proposed for creating the tectonic features of Antarctica Mantle plume Localized thermal anomaly http://mitglied.lycos.de/mapu2001/dryvalleys.html

  6. Previous studies show a negative anomaly beneath the Ross Sea at 300 km Watson 2005 Seiminski et al 2003

  7. Clapeyron Slopes Phase transformation at ~ 410 km Phase transformation at ~660 km Bina and Helffrich, 1994

  8. The thermal anomalies affect the depth of the major phase transformations

  9. TAMSEIS The Transantarctic Mountains Seismic Experiment (2000 - 2003) included 41 portable broadband seismometers http://epsc.wustl.edu/admin/whatsnew/tamseis/

  10. Three arrays: Coastal array North array East array http://epsc.wustl.edu/admin/whatsnew/tamseis/

  11. Receiver functions generated using Ammon’s water level-deconvolution code and stacked using Owen’s stacking codes. http://eqseis.geosc.psu.edu/~cammon/HTML/RftnDocs/rftn01.html http://epsc.wustl.edu/admin/whatsnew/tamseis/

  12. Maps of the points show the lateral extent of the ray sampling from teleseismic events 410 km cross-sectional slice 660 km cross-sectional slice

  13. Some results

  14. A B C D E ‘410’ C E A ‘660’ D B EAC Ross I.

  15. Preliminary(?) Results: The ice layer is not causing the double peak but what is? AND The average transition zone thickness is greater than 250 km (the global average) -- currently no evidence for a plume or thermal anomaly in the transition zone http://home.freeuk.com/gtlloyd/tam/main.htm

  16. Any questions?

  17. Geographical binning reduces bias based on azimuth latitude longitude

  18. Each bin table is populated by the names of station/event pairs for which the wave passed through that node as well as the time that this occurs Station1-eventA Station1-eventG Station3-eventA, etc Node size 1° by 2° A t t*

More Related