118-4 Devastation of a Coastal Aquifer from the Most Powerful Storm Ever: A Story of Resilience and Recovery

Session: Groundwater in Achieving the Sustainable Development Goals

Presenting Author:

Author:

Abstract:

The northwest Pacific Ocean is a hot spot for sea level rise and increasing frequency of stronger storms. It is where Supertyphoon Haiyan formed, the strongest storm on record to hit land, which provided a window into the hydrologic impacts of an extreme storm. This talk presents results of detailed documentation of flood levels, groundwater table elevations, groundwater geochemistry, electrical resistivity, and flow and transport modeling. Through repeat surveys soon after the storm, we found that Haiyan's storm surge reached 7 m above sea level along Samar Island, Philippines, which led to contamination of crucial aquifers by infiltrating seawater. The seawater infiltration had short- and longer-term effects. A contaminated surficial aquifer would take years to recover. While groundwater in an underlying deeper aquifer saw widespread contamination immediately after the storm, salinity decreased significantly after 8 months. However, this deeper aquifer remains vulnerable to seawater slowly percolating through the surficial aquifer. As warmer seas generate more powerful storms, the vulnerability of aquifers to persistent contamination from intense storm surges is a growing concern for coastal communities.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-8571

© Copyright 2025 The Geological Society of America (GSA), all rights reserved.