  Mars' tadpole craters are small, young craters whose crater rims are incised
by one or more exit breaches but lack visible inlets. The tadpole forming
climate records the poorly understood drying of Mars since the Early Hesperian.
A third of tadpole craters have multiple breaches, therefore a process is
needed that was able to generate crater rim incision in multiple locations. We
use HiRISE data for four multiple breach tadpole craters to measure their
crater fill, rims, and exit breaches. We compare these measurements and other
data to our calculations of liquid water supply by rain, surface melting,
groundwater discharge, and basal ice sheet melting to discriminate between four
proposed formation hypotheses for tadpole breaches, favoring scenarios with
ice-filled craters and supraglacial melting. We conclude that multiple breach
tadpole craters record hundreds of meters of mid-latitude ice and climate
conditions enabling intermittent melting in the Late Hesperian and Amazonian,
suggesting that liquid water on Mars has been available in association with
water ice for billions of years.
