Host: The Japanese Society for Planetary Sciences: Local Organizing Committee for 2006 Fall Meeting
The morphology and location of outflow channels on Mars indicate a subsurface origin of the water (e.g., [1]). However, the origin and processes that can provide the large inferred discharge, is not well understood. Following previous studies, we hypothesize that dike intrusion played a significant role [2]. We quantify, using numerical models the conditions, the conditions under which dikes may permit large discharges of water. We perform 2-D numerical simulations of the amount and distribution of meltwater adjacent to a cooling dike to test the hypothesis. We extend HYDROTHERM code developed by the USGS [3] and include the effects of the phase transition between ice and water. We thus account for both boiling and freezing. The interaction between magma and frozen ground is assumed to occur at depths between several kilometers and a few hundred meters depth. At the depths, boiling may occur without direct sublimation. We evaluate the melting process of the permafrost layer by estimating the following: (1) How much meltwater an be generated? (2) What is the pattern of hydrothermal circulation?, and (3) How fast does the dike cool? References.[1] Manga, M. (2004) [2] Ogawa, Y., Y. Yamagishi and K. Kurita (2003) [3] Hyba, D. O. and S. E. Ingebristen (1997).
