COLLABORATIVE RESEARCH: Continuation of a GPS-Based Study of Slip Along The Rivera Subduction Interface Following the October 9, 1995 Mw=8.0 Jalisco Earthquake

我们建议使用墨西哥西部现有的24站GPS网络，继续对里维拉和北科科斯俯冲带进行基于GPS的研究。我们的具体目标是区分深度弹性滑动和深度粘性流动模型对地震后运动的预测，确定地震后滑动是否在地震后几年内衰减并立即恢复稳定的震间应变积累，评估地震间应变积累是否集中在容纳最大同震滑移的部分俯冲界面上，确定同震破裂的屏障(例如，速度加强区)是否对应于显著余滑的区域，正如预期的那样，俯冲断层上的摩擦遵循速率和状态变化的本构规律，并确定地震间应变积累是否与完全锁定的断层一致正如预期的板块滑落与同震释放的滑块的比较所表明的那样。为了实现这些目标，我们将继续每年和连续地占领该网络，并对地震后的位移进行密集的建模。

We propose to continue a GPS-based study of the Rivera and northernCocos subduction zones using an existing 24 site GPS network in westernMexico. Our specific goals are to discriminate between the predictionsof elastic-slip-at-depth and viscous-flow-at-depth models forpostseismic motion, to determine whether postseismic slip decays within afew years of the earthquake and is immediately followed by a resumptionof steady interseismic strain accumulation, to assess whether interseismicstrain accumulation is focused along parts of the subduction interfacethat accommodated the most coseismic slip, to determine whetherbarriers to the coseismic rupture (e.g. velocity-strengthening regions)correspond to regions of significant afterslip, as might be expected iffriction along the subduction fault obeys rate- and state-variableconstitutive laws, and to determine whether interseismic strainis consistent with a fully-locked fault, as comparisons of expected plateslip versus coseismically-released slip suggest. Toward these goals,we will continue annual and continuous occupations of the network,and intensive modeling of postseismic displacements.