CRUSTAL STRUCTURE ALONG THE TRANSANTARCTIC MOUNTAIN FRONT USING RECEIVER FUNCTIONS

Open Access
Author:
Finotello, Marco
Graduate Program:
Geosciences
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
June 15, 2009
Committee Members:
  • Andrew Arnold Nyblade, Thesis Advisor
  • Jordi Julia, Thesis Advisor
Keywords:
  • TAMSEIS
  • Receiver Functions
  • Crustal Structure
  • Transantarctic Mountains
Abstract:
In this study, we investigate crustal structure along the Transantarctic Mountains (TAM) in the vicinity of Ross Island using teleseismic waveforms recorded by 16 stations of the Transantarctic Mountain Seismic Experiment (TAMSEIS) and three permanent stations. Beneath many of these stations there is a ~200-300 K mantle thermal anomaly that is associated with the Ross Island volcanic complex and by examining crustal structure we can determine to what extent the crust may have been magmatically modified. Receiver functions were computed using an iterative deconvolution method and analyzed using the H-κ stacking method and the method of Zandt et al. (1995). Crustal thickness (H) estimates along the coast range from 25 to 33 km and increase to ~39 km inland beneath the crest of the TAM. On Ross Island, crustal thickness estimates range between ~20 to ~27 km. A Vp/Vs ratio (κ) of 1.88 is obtained for Ross Island, consistent with the mafic composition of the volcanic rocks from Mt. Erebus. Vp/Vs ratios for stations along the TAM range from 1.63 to 1.78, with an average of 1.73, indicating a felsic to intermediate composition crust. This result suggests that the crust along the TAM front has not been magmatically altered by the mafic volcanism associated with Ross Island, and that the mantle thermal anomaly is not likely associated with partial melting of the crust away from Ross Island.