A geographical sound is a significant and distinctive body of water that plays an important role in coastal environments. It is generally a smaller body of water connected to a larger sea or ocean, forming an inlet that is often wider than a fjord. These features are frequently found along coastlines and are known for providing relatively protected waters for navigation and ecosystems.
Defining the Geographical Sound
A sound is a large sea or ocean inlet that typically forms an extensive, protected waterway. This body of water can take one of two general forms: a wide indentation of the sea into the land, or a channel of water separating a mainland coast from a nearby island or archipelago. For example, Long Island Sound separates the coast of Connecticut from Long Island, New York.
The dimensions of a sound make it a deep enough and wide enough passage to be navigable. The water within a sound is often a mix of freshwater runoff from the land and saltwater from the ocean, creating a brackish environment that supports unique marine life. Due to the surrounding landmasses, sounds offer a protected anchorage, shielding vessels from the full force of open-ocean waves and currents.
Geological Processes That Form Sounds
The formation of a geographical sound is directly linked to major geological and climatic events, primarily sea-level rise and glacial activity. One common mechanism involves the submergence of a river valley, which results in a feature known as a ria. As the sea level rises, the ocean floods the lower, seaward portion of the river valley, creating a long, branching inlet characterized by gently sloping valley sides that continue underwater. The Marlborough Sounds in New Zealand are a well-known example of this drowned river valley formation.
Another method of formation involves the erosive power of ancient glaciers. Glacial sounds form when a massive ice sheet carves a U-shaped valley down to the coast, and the subsequent melting and retreat of the glacier allows the sea to flood the deep basin. These glaciated sounds often have steep, near-vertical sides and can be significantly deeper at the landward end due to moraine deposits left by the retreating ice. While these features are technically fjords, they are sometimes geographically named sounds, such as Puget Sound in Washington State.
Distinguishing Sounds from Straits, Bays, and Channels
The term “sound” is often used interchangeably with other coastal terms, but geographical differences exist, especially in their form and function. A sound is much wider and more spacious than a strait, which is a narrow, naturally formed waterway connecting two larger bodies of water. Straits are primarily connectors, while sounds can be either an inlet or a broad channel separating landmasses. The Øresund, which separates Denmark and Sweden, is a rare example of a sound that also functions as a major strait connecting the North Sea and the Baltic Sea.
A bay, in contrast to a sound, is an indentation of the coastline that is partially enclosed by land, usually on three sides, and has a single, broad opening to the sea. Sounds are generally wider than bays and often have multiple connections to the open ocean or larger bodies of water. For instance, a sound may be a long channel running parallel to the coast, separated from the open sea by a chain of barrier islands, such as North Carolina’s Pamlico Sound.
The difference between a sound and a channel is often one of scale and context. A channel is a general term for a navigable passage, which can be natural or artificial. Geographically, a sound implies a larger, more permanent waterway, often defined by a specific formation history as a flooded valley or an area separating a large island from the mainland. While a channel can be simply the deepest part of a waterway, a sound refers to the entire broad body of water itself, making it a more comprehensive geographical designation.