Time-Lapse: Glacial Outburst Causes Flooding in Juneau, Alaska Glacial lakes form in valleys where ice has melted and are blocked by glaciers or debris. As these lakes fill with water, pressure can cause a sudden release downstream, known as a glacial lake outburst flood. These events are sudden and can be devastating. This time-lapse from May 1st to August 7th captures the dramatic rise and fall of water levels in Suicide Basin during the outburst. The basin was formed as rising temperatures re