White Park Bay in Northern Ireland is a pleasant place for walking and there is lots of interesting geology: raised beach with caves in chalk, lots of flint nodules, basaltic rocks, fluvial sand enriched in heavy minerals, and last but not least, a squeaking sand.
It was fun to drag boots through the sand and listen to the music sand grains are making. I took a short video to record that squeaking sound:
This sand was not squeaking everywhere. The sand has to be dry but not very loose. Squeaking part of the beach was relatively firm and easy to walk on.
This squeaking sound is pretty common and it is different from booming sand which is associated with sandy and very dry deserts with loose sand. Booming sound also has a lower pitch. It is still an open question what causes the squeaking and booming sounds but it seems to be obvious enough that friction between quartz grains is the triggering mechanism. It is thought that grains have to be well-rounded, well-sorted, and free of dirt. If you want to know more about squeaking and booming sands, check out this article.