Fig. 4: Reconstructed water-table depths in the San Diego region.
From: Deglacial water-table decline in Southern California recorded by noble gas isotopes
Noble gas isotope-derived water-table depths (WTD) from the San Diego aquifer system are presented in meters below the land surface. Blue markers and error bars (±2σ) indicate WTD derived from individual samples collected from wells at multiple depths at six sites (indicated by marker shapes). Pre and post 15-ka mean WTDs (lines with ±2-SE shaded regions) exclude two extreme WTD observations that could reflect a previously documented glacial dry period and wet Younger Dryas stadial. The present-day mean WTD over the assumed recharge area (inset) was estimated by a high-resolution, observation-constrained groundwater model (red square marker). Groundwater age uncertainties are roughly ±2 ka (Supplementary Note 4).
