Wed, Oct 5, 2016

Is it an arch or a bridge?

Natural bridges are created when a meandering stream forms a big looping curve that all but circles back on itself, leaving a thin wall separating the flow.  The water erodes both sides of the wall and eventually punches through creating a bridge.

So there’s the answer.  Natural bridges are formed by erosion from moving water while arches are formed by other erosive forces such as the water – ice freeze cycle.

The Natural Bridges park encompasses White Canyon that is deep with near vertical walls. The stream meanders its way through the canyon and has created three large bridges.

One of them, Sipapu Bridge, is the second largest natural bridge in the world behind only Rainbow Bridge in Glen Canyon.  In the photo below, you can see the original loop of the stream and the wall that eroded away to create the bridge.