Saturday, March 24, 2007
The Kelso Dunes
The Kelso Dunes cover 45 square miles just southwest of Kelso, California, in the Mojave National Preserve (a 1.6 million-acre tract within the Mojave Desert). The dunes are about 700 feet high, and were created over a span of 25,000 years by winds carrying grains of sand from the northwest. The sand was stopped in its path by mountains to the south and east. The dunes are golden in color, contrasting with the much darker hues of the surrounding topography.
These dunes share an interesting characteristic with some 30 other dunes around the world: they make an odd booming sound (similar to that of a low-flying airplane) when sheets of sand cascade down and rub against stationary sand below. Always eager to experience some free entertainment, we hiked over a mile through the sand until we reached dunes of sufficient slope to create the odd sounds.
The going was not easy, and Mom was a real trooper. It requires some effort to trudge through soft sand, and soon our shoes and socks were full of it. The temp rose to the upper 80s in the early afternoon, and when we reached the steeper slopes the sweat started to pour. It was interesting all along the way to see fringe-toed lizards quickly dart underfoot to the safety of nearby creosote bushes.
Finally we reached a sufficient gradient to create the booming. By running down the steep slope, causing sand to tumble below, I heard what to me sounded like “Thoom Thoom Thoom”. Susan believes the sound is “Whump Whump Whump,” but no matter. The sand really does vibrate like a musical instrument!