The Changing Shore
T HE road to Holiday Shore runs through meadows and past the farm at the foot of Holiday Hill. Then it winds through woods and crosses a stream. This is the stream up which the alewives and some other fish swim to lay their eggs in Holiday Pond.
At last the road comes near the sea. On windy days you can hear the waves as they break on the rocks. When the big waves come in and break like that, you can see how Holiday Shore was made, and why it changes every year.
For the shore really does change. Look at that rocky point: it was once bigger than it is to‑day. To be sure it seems firm and unchangeable while the water of the quiet sea ripples on the rocks at its foot. Even on stormy days the point still holds itself strong and steady against huge waves that roll in from the bay. They dash against its hard gray stone and splash into fine, white spray that the wind carries far inshore. How can waves that break into weak misty spray change the shape of Holiday Point?
Stand behind this old, twisted tree and see a little of what storm waves can do to the shore. Here comes a big one now; watch it fill every hole and crack. Will it succeed in pushing the rocks apart?
After the wave has broken against the point and the water has run back toward Holiday Bay, you will see pieces of rock come loose and whirl away in the water. Every piece leaves a crack to mark the place from which it fell. When these cracks become deep enough, larger blocks of stone will be loosened to fall from the cliff. You may find blocks on Holiday Point that seem almost ready to fall.
When they go down, they will lie among the other rocks in the foaming water. Waves will bump them together, small rocks will be pushed against them, and sand will be scrubbed over their faces. All this rubbing will wear away rough bits from the rocks. It may take only a year or so for the waves to turn sharp-edged rocks into rounded stones like those that lie on the sandy part of Holiday Shore.
Stones worn round by water are called cobbles. Some cobbles are very large. They are blocks that fell from the cliff only a few years ago. Others are small and very smooth. They have been tossed and pounded so long that most of their mass has been carried away. A few were dropped by melting glaciers that once came down from the north and covered the cliffs of Holiday Shore. When the glaciers dropped them, these stones were scratched, but waves have worn their faces smooth.
You can hear the cobbles being ground together. A strong wave rolls up the shore. Listen as the wave breaks and the water runs back to the sea. Clatter-clatter-clatter go the cobbles as they roll about and hit one another. And clackety-clackety-clack go the pebbles that once were cobbles themselves, but have been worn down until they are little. Some day they will be only grains of sand as tiny as those on the beach that covers part of Holiday Shore.
So you see how waves may change the coast. Once it was a straight line of cliffs. Then the waves found a place where they could break off chips of rock, and let big stones fall into the water. They kept this up year after year. In time they dug a little cove. After hundreds and thousands of years, the cove grew big enough to be a bay. You have seen that it is still growing to‑day as the waves break on its shore.
What happened to all the rock and sand that was dug out to make Holiday Bay? Part of it was worn so very fine that it drifted far away on the waves. When it did settle to the bottom of the ocean, it was many miles from shore. Much stayed in the bay itself. A great deal still lies on the shore or in the shallow water near by.
To study the sands of Holiday Shore, we shall come on a quiet, sunny day. We should choose a time when the tide is low, so that we can walk along the beach and wade far out in the shallow water.
We may dig holes in the wet sand, finding worms, sand dollars, and white-shelled clams that spend their lives burrowing in it. It is not well to waste the clams. So, unless you wish to cook them for a meal, throw your clams back into the water or give them to people who may use them for food.
As your spade turns up sand from the beach, you find that it lies in layers or beds like many rocks that stand on land. Some layers go this way and that, as the waves or currents dropped the sand. If you pry or dig into the bedrock of Holiday Hill you may find stones that show the same kind of crisscrossed layers. Then you will know that they were formed near shore very, very long ago.
Now let us go to a place where the water hardly covers the sand. It ripples under the summer breeze—and looking at the beach we find ripples like those in the water.
If the sand were to become hard stone, most of those ripples would be preserved. There are many places where you can find sandstones that are millions and millions of years old. And they show the marks of rippling waves like those we now see on the beach even though they may be miles from any ocean. Surely in the ages when the earth was young the sea waves must have rippled over countless shores that are now far inland.
As the coast changes and is worn by waves, the things that live upon it change their homes. When Holiday Shore inclosed a little cove, barnacles and rock mussels lived where we now find sand with seaweeds and clams. Perhaps a hundred years from to‑day that cliff will have crumpled and become a pile of cobbles where snails and crabs will crawl.