Ever notice how, when you take a bath, the water sloshes around when you move? The same thing happens when you scoot a cup of liquid around on a table. That sloshing movement happens on a large scale, too, in lakes and bays. It’s called a seiche (pronounced saysh), French for “to sway back and forth.” When the weather is calm, most of these bodies of water are pretty placid. But when winds pick up, when atmospheric pressure changes quickly or even when there’s enough seismic activity like an earthquake, it pushes water around, often away from the shore. In extreme cases, water retreats for so long that many people mistake it for a tide.
