The recent comparison of volcanic landscapes in Hawaiʻi and El Salvador by the U.S. Geological Survey (USGS) Hawaiian Volcano Observatory scientists highlights some fascinating differences. While Hawaiʻi's volcanic activity is currently quiet, with Kīlauea building up to its next high lava fountaining episode, the comparison with El Salvador offers a unique perspective on volcanic dynamics. El Salvador, a small country in Central America, has a population of about 6 million, which is about four times that of Hawaiʻi. However, the number of volcanoes is vastly different. El Salvador has over 200 volcanoes, while Hawaiʻi has only 15 above sea level. This disparity is due to their geological settings: El Salvador sits along the Central American volcanic arc, where an oceanic tectonic plate subducts beneath another oceanic plate, triggering melting and magma formation. In contrast, Hawaiʻi is a hotspot, where a stationary plume of hot material rises through the Earth's mantle, creating a chain of volcanoes. The comparison is particularly intriguing when considering the monitoring and research efforts in both regions. The USGS, through its Volcano Disaster Assistance Program (VDAP), has a long-standing collaborative relationship with the Ministerio de Medio Ambiente y Recursos Naturales (MARN) in El Salvador. VDAP has supported technical investigations and monitoring projects, while MARN volcanologists have studied in the U.S. as part of the Center for the Study of Active Volcanoes (CSAV) course. The recent fieldwork in El Salvador focused on describing the eruptive history and hazards of Santa Ana volcano and assembling a national volcano atlas. This atlas will include data on locations, compositions, and approximate ages of the over 200 volcanic vents, enabling a more accurate understanding of associated hazards. The USGS scientists learned valuable insights about volcanism in El Salvador, particularly regarding the interactions between lava flows and weathered depositional environments, which are similar to some of Hawaiʻi's older volcanoes. This comparison highlights the importance of understanding the unique characteristics of each volcanic region. While Hawaiʻi's volcanic activity is currently relatively calm, the ability to interpret explosive eruption deposits is crucial for assessing future hazards. The distributed nature of volcanoes in El Salvador provides a different perspective on lava flow interactions with the environment, offering valuable lessons for Hawaiʻi's older volcanoes. The collaboration between the USGS and MARN not only enhances volcanic hazard awareness in El Salvador but also contributes to a deeper understanding of volcanic processes in Hawaiʻi, fostering a global exchange of knowledge and expertise in volcanology.
