a, Rainfall data obtained from the Hawai‘ian Beaches rain gauge (refer to Fig. 1a inset for location). b, Data from the Paradise Park well (see Fig. 1a inset for the location of the well), digitized from ref. 51 over the time period October 1992–June 1993. c, Pressure evolution at a depth of 1 km modelled using rain data from a. Grey bars highlight peaks evident in well-level data that are echoed in the modelled data on pore-pressure change. Note that well level serves as a proxy for pressure change, dependent on well depth and bore, inertia, storage capacity, tidal effects and atmospheric pressure: these factors are not considered in this illustrative example.