The Costa Rica Seismogenesis Project (CRISP)(IODP Expedition 334) was carried out on the continental margin slope apron in the Costa Rica subduction zone in Central America. The primary scientific goals of this expedition are to understand the processes that control nucleation and seismic rupture of large earthquakes at erosion-controlled subduction zone. During one month drilling, onboard totally 1 492.88 meters long cores were obtained at four sites and eight holes. Tephra layers with ages ranging from Miocene to present were indentified. Rock variation characteristic of sediments and basement rocks were preliminary defined and basalt from the oceanic Cocos ridge basement was recovered.