Future occurrence of explosive eruptive activity at Cotopaxi and Guagua Pichincha volcanoes, Ecuador, is assessed probabilistically, utilizing expert elicitation. Eight eruption types were considered for each volcano. Type event probabilities were evaluated for the next eruption at each volcano and for at least one of each type within the next 100 years. For each type, we elicited relevant eruption source parameters (duration, average plume height, and total tephra mass). We investigated the robustness of these elicited evaluations by deriving probability uncertainties using three expert scoring methods. For Cotopaxi, we considered both rhyolitic and andesitic magmas. Elicitation findings indicate that the most probable next eruption type is an andesitic hydrovolcanic/ash-emission (~ 26–44% median probability), which has also the highest median probability of recurring over the next 100 years. However, for the next eruption at Cotopaxi, the average joint probabilities for sub-Plinian or Plinian type eruption is of order 30–40%—a significant chance of a violent explosive event. It is inferred that any Cotopaxi rhyolitic eruption could involve a longer duration and greater erupted mass than an andesitic event, likely producing a prolonged emergency. For Guagua Pichincha, future eruption types are expected to be andesitic/dacitic, and a vulcanian event is judged most probable for the next eruption (median probability ~40–55%); this type is expected to be most frequent over the next 100 years, too. However, there is a substantial probability (possibly >40% in average) that the next eruption could be sub-Plinian or Plinian, with all that implies for hazard levels.

厄瓜多尔的科托帕希和瓜瓜·皮钦查火山在未来发生爆炸性爆发活动的可能性，是根据专家的启发进行概率评估的。每个火山考虑了八种喷发类型。在接下来的100年中，针对每个火山的下一次喷发以及每种类型中的至少一种对类型事件概率进行了评估。对于每种类型，我们都得出了相关的喷发源参数（持续时间，平均羽流高度和总提夫拉质量）。我们通过使用三种专家评分方法得出概率不确定性来研究这些评估的鲁棒性。对于Cotopaxi，我们同时考虑了流纹岩浆和安山岩浆。启发性研究结果表明，最有可能的下一次喷发类型是安第斯山脉的火山/火山灰排放（中位概率约为26–44％），在接下来的100年中，其复发的中位机率最高。但是，对于科托帕希的下一次喷发，亚普林尼亚或普利尼亚类型喷发的平均联合概率约为30％至40％-发生剧烈爆炸事件的可能性很大。可以推断，与麻醉药事件相比，任何Cotopaxi的流产性火山喷发都可能伴有更长的持续时间和更大的爆发质量，可能会导致紧急情况的延长。对于瓜瓜（Guagua Pichincha），预计未来的喷发类型为安第斯山脉/大洋洲，并且下一次喷发被认为是最有可能发生的火山爆发事件（中位概率约为40-55％）。预计这种类型在未来100年内也是最常见的。但是，下一次喷发很有可能（平均> 40％）是次普林尼期或普林尼期，