Oil spills near tropical coastlines can seriously threaten the groundwater people rely on, mainly because heavy oils tend to get trapped underground and stick around for a long time in the mixed-up layers of soil and rock. In this study, researchers from National Taiwan Ocean University’s Institute of Earth Sciences used gas chromatography-mass spectrometry (GC-MS) in their running of a detailed lab experiment over 48 weeks at room temperature (25°C) to see how two types of heavy fuel oil (Teh Shiang Taipei and Tzimini) break down and change chemically over time once they’re trapped underground. A paper based on this work was published in the journal Marine Pollution Bulletin.
- Rapid volatilization and dissolution remove light fractions, increasing viscosity and promoting pore-scale trapping that limits lateral migration yet sustains chronic subsurface petroleum reservoirs for decades.
- GC–MS kinetics showed early near-complete loss of the most mobile compounds, consistent with fast initial weathering followed by prolonged persistence of the remaining high-molecular-weight matrix.
