SAND PETROLOGY AS A PROXY FOR EXTREME WAVE EVENTS, A CASE STUDY FROM ANEGADA, BRITISH VIRGIN ISLANDS

Sand petrology has been used in many studies in different geographic settings throughout the world as a signature for tsunami deposits. Its reliability as a definitive proxy for extreme waves however, remains controversial. In Anegada, British Virgin Islands (BVI) the presence of predominantly elongated sand grains in combination with the foraminifera Homotrema Rubrumwere found in a number of locations far inland. The presence of these grain rods might not be an exact indicator for tsunamis activity, however, two different tsunami inundation models for Anegada show waves extending as far inland as the south shore of the Island. The two different models suggest that both grain types could have been transported inland by extreme waves. The origin of both grain types will be discussed thoroughly as well as a visual reference of two possible scenarios on how these two different types of grains could have been deposited far inland from their offshore origin

1. Outer Rise M 8.2 Tsunami

1. Subduction Thrust M 8.45 Tsunami 

This abstract was adapted, from a journal manuscript by B.F. Atwater, U.S. ten Brink, A.L. Cescon, N. Feuillet, Z. Fuentes, R.B., Halley, C. Nunez, E.G. Reinhardt, J.H. Roger, Y. Sawai, M. Spiske, M.P., Tuttle, Y. Wei, and J. Weil Accardo.