Here is the article to go with the story about rain in the Atacama desert – overflowing crater lakes caused canyons to be cut out on Mars (go to https://phys.org/print461597820.html …). We are told that billions of years ago water flowed freely across Mars. Former rivers erupted into craters, forming lakes and seas. Sometimes these lakes became so filled with water they overflowed – creating catastrophic flooding events. They go on to sugegst that catastrophic geological processes may have played a major role in shaping the landscape of Mars. They also keep their tinder dry as they say that this could not happen on Earth because we have Plate Tectonics. In other words, in a non Plate Tectonics world catastrophies are feasible – but not in the special case of the Earth. Having said that they go on to use a catastrophic flooding event on Earth as proof of their hypothesis – the Scablands (formed during a pulse of meltwater at the end of the Ice Age). Some of the lakes were as large as the Caspian Sea, it would seem, so these are not small bodies of water, the inference being they were comparable to lakes that built up at the bottom of the ice sheets as a result of an ice dam which when it breached caused huge amounts of water to wash across the landscape of the Earth (as occurred with the Scablands and as has been found at the bottom of the Straits of Dover etc).