Ms. Maria Jhonnie Villareal, December 2021 graduate. Committee: Jenson, King, and Aban.For her thesis, Ms. Villareal mapped Ayuyu Cave, a coastal cave 65 m long with 3500-m3 volume, from which a freshwater spring discharges 2.3 MGD from the Finegayan Groundwater Basin of the Northern Guam Lens Aquifer. She documented a complex speleogenetic history, which includes the known cycles of Pleistocene eustatic sea level fluctuation concurrent with irregular episodes of local tectonic uplift and subsidence of unknown timing, magnitude, and duration. Features characteristic of vadose, phreatic, and flank margin caves are overprinted such…