Costa Rica has been affected by several local and distant tsunamis in the past, but the historical information is scarce and incomplete. Its Pacific coast stretches for over a thousand kilometers, and tsunami hazard has never been evaluated for its full extent. Numerical modeling of tsunami propagation and inundation is a useful tool to assess tsunami hazard, particularly in cases with limited historical information available. Here, we perform a first estimation of tsunami hazard for the Pacific coast of Costa Rica from seismogenic sources, by numerical propagation of 57 local and distant tsunamis to a depth of 20 m. The results of our study identified tsunami sources that are particularly threatening for Costa Rica and determined locations with higher tsunami hazard. For the analysis, the Pacific coast of Costa Rica was divided into segments and subsegments based on differences in continental slope morphology. Subsegments with higher tsunami heights were Southwest Nicoya Peninsula and West Osa Peninsula, and in a lesser extent North Guanacaste, North Nicoya Peninsula, and Central Pacific. Regions with long and gentle slopes and narrow continental shelf were affected by higher tsunami waves, due to more efficient tsunami energy transmission to the shelf and reduced energy loss while traveling through a narrow shelf. On the opposite, steeper continental slopes reflected most of the tsunami energy, causing smaller tsunami heights nearshore, regardless of the shelf width. Nevertheless, other effects played a major role, like curved coastlines that focused tsunami energy, wave refraction, interference, and trapped edge waves. Distant tsunamis dominated the threat, with tsunamis coming from the Tonga-Kermadec and the Colombia-Ecuador Trenches causing the greatest heights due to directivity, and arrival times of about 15 h and 75 min, respectively. Local tsunamis had short arrival times but a localized impact, mainly at the shoreline in front of the generation region but were also affected by tsunami focusing, wave refraction, and edge waves. Outer rise and Osa sources caused the lowest impact within local sources. These results provide a guide for emergency planners to prioritize coastal locations and tsunami sources for tsunami preparedness actions and warning protocols.

哥斯达黎加过去曾受过几次本地和远距离海啸的影响，但历史资料稀少且不完整。它的太平洋海岸绵延一千多公里，海啸灾害从未对其进行过全面评估。海啸传播和淹没的数值模拟是评估海啸灾害的有用工具，尤其是在历史信息有限的情况下。在这里，我们通过 20 m 深度的 57 次本地和远处海啸的数值传播，从地震源对哥斯达黎加太平洋沿岸的海啸危害进行了首次估计。我们的研究结果确定了对哥斯达黎加特别具有威胁的海啸来源，并确定了海啸危害较高的地点。对于分析，哥斯达黎加太平洋沿岸根据大陆坡形态的差异分为段和亚段。海啸高度较高的子区段是西南尼科亚半岛和西奥萨半岛，其次是北瓜纳卡斯特、北尼科亚半岛和中太平洋。由于海啸能量传输到大陆架的效率更高，穿过狭窄大陆架时的能量损失减少，因此斜坡长而平缓和大陆架狭窄的地区受到更高的海啸波的影响。相反，更陡峭的大陆斜坡反射了大部分海啸能量，导致近岸海啸高度变小，而与大陆架宽度无关。然而，其他影响发挥了重要作用，例如弯曲的海岸线会聚集海啸能量、波浪折射、干扰和被困边缘波浪。远处的海啸是威胁的主要因素，来自汤加-克马德克海沟和哥伦比亚-厄瓜多尔海沟的海啸由​​于方向性和到达时间分别约为 15 小时和 75 分钟，造成了最大的高度。局地海啸到达时间短，但具有局部影响，主要发生在发生区前方的海岸线上，但也受到海啸聚焦、波浪折射和边缘波的影响。外部上升和 Osa 源对本地源的影响最小。这些结果为应急计划人员为海啸准备行动和预警协议确定沿海位置和海啸源的优先顺序提供了指南。和到达时间分别约为 15 小时和 75 分钟。局地海啸到达时间短，但具有局部影响，主要发生在发生区前方的海岸线上，但也受到海啸聚焦、波浪折射和边缘波的影响。外部上升和 Osa 源对本地源的影响最小。这些结果为应急计划人员为海啸准备行动和预警协议确定沿海位置和海啸源的优先顺序提供了指南。和到达时间分别约为 15 小时和 75 分钟。局地海啸到达时间短，但具有局部影响，主要发生在发生区前方的海岸线上，但也受到海啸聚焦、波浪折射和边缘波的影响。外部上升和 Osa 源对本地源的影响最小。这些结果为应急计划人员为海啸准备行动和预警协议确定沿海位置和海啸源的优先顺序提供了指南。