High hydrogen outgassing from an ophiolite-hosted seep in Zambales, Philippines

• Published in: International journal of hydrogen energy 2025-03, Vol.105, p.360-366
• Main Authors: Aquino, Karmina A., Perez, Americus dC, Juego, Candy Mariel M., Tagle, Yzanx Grano M., Leong, James Andrew M., Codillo, Emmanuel A.
• Format: Article
• Language: English
• ISSN: 0360-3199
• DOI: 10.1016/j.ijhydene.2025.01.251

Naturally produced by geochemical processes in the Earth's crust, geologic hydrogen is recently considered as an alternative energy source that may help decarbonize the energy sector. We present field-based hydrogen flux measurements from natural seeps and springs emanating from ultramafic rocks in the Zambales ophiolite, Philippines, where hydrogen is produced from water-rock interactions. We record at least 808 tons/year of natural surface outgassing from the Nagsasa seep alone, which is one of, if not, the highest measured hydrogen degassing from ophiolites to date. This outgassing is significant and may supplement the power demand of the town of San Antonio which is hosting the seep. This highlights the potential of geologic hydrogen to provide access to energy especially in rural areas, where these ophiolites are often located in the Philippines. [Display omitted] •Surface H2 flux in Zambales ophiolite is the highest reported in ophiolites to-date.•Unlike in fairy circles, the H2 flux in the seep is continuous.•H2 flux is likely fed by a deeper subsurface reservoir of accumulated H2.