Submarine groundwater discharge (SGD) in volcanic areas commonly exhibits high temperatures, concentrations of metals and CO₂, and acidity, all of which could affect sensitive coastal ecosystems. Identifying and quantifying volcanic SGD is crucial yet challenging because the SGD might be both discrete, through fractured volcanic rock, and diffuse. At a volcanic area in the Philippines, the novel combination of satellite and drone-based thermal infrared remote sensing, ground-based fiber-optic distributed temperature sensing, and in situ thermal profiling in coastal sediment identified the multi-scale nature of SGD and quantified fluxes. We identified SGD across ∼30 km of coastline. The different approaches revealed numerous SGD signals from the intertidal zone to about a hundred meters offshore. In active seepage areas, temperatures peaked at 80°C, and Darcy fluxes were as high as 150 cm/d. SGD is therefore locally prominent and regionally important across the study area.

中文翻译：

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火山区沿海生态系统海底地下水流量多尺度热图


火山区的海底地下水排放 （SGD） 通常表现出高温、金属和 CO₂ 浓度以及酸度，所有这些都可能影响敏感的沿海生态系统。识别和量化火山岩 SGD 至关重要，但也具有挑战性，因为 SGD 可能既是离散的、穿过裂隙火山岩的，也可能是弥散的。在菲律宾的一个火山区，基于卫星和无人机的热红外遥感、地面光纤分布式温度传感和沿海沉积物的原位热分析的新组合确定了 SGD 和量化通量的多尺度性质。我们在大约 30 公里的海岸线上确定了 SGD。不同的方法揭示了从潮间带到离岸约 100 米的大量 SGD 信号。在活跃的渗流区，温度达到 80°C 的峰值，达西通量高达 150 cm/d。因此，SGD 在整个研究区域中具有局部突出和区域重要性。