Puget Sound

Puget Sound is a big area of salt water.

It sits in Washington state. Many big cities are near the water.

A long time ago, huge sheets of ice covered this land. The heavy ice moved the ground. As the ice melted, it made the deep water we see today. You can find seals in the water there. It is a very special place.

Puget Sound is a large area of salt water.

It sits on the coast of Washington state. It is part of the Salish Sea. This system connects to the Pacific Ocean through the Strait of Juan de Fuca.

Many big cities sit near the water. These include Seattle, Tacoma, Olympia, and Everett.

A long time ago, huge sheets of ice covered this land. The heavy ice moved and shaped the ground. As the ice melted, it made deep valleys. These valleys filled with water to make the Sound.

The water moves in and out with the tides. This creates strong currents in some spots.

Many living things call this place home. You might see a harbor seal near the coast. Sea plants like kelp grow under the waves. These plants help many animals. The water is a mix of salt and fresh water. This makes it a very special home for sea life.

Puget Sound is a huge system of saltwater waterways.

It sits on the northwest coast of Washington state. This area is part of a larger group of waters called the Salish Sea. The Sound connects to the Pacific Ocean through the Strait of Juan de Fuca. There are several ways the water flows in and out. One major path is through Admiralty Inlet. Two smaller paths are Deception Pass and the Swinomish Channel.

It is the second-largest estuary in the United States. The first largest is Chesapeake Bay.

The shape of the Sound was made by ice. Long ago, massive ice sheets covered this whole region. This was part of the Vashon Glaciation. The ice was very thick near Seattle. It even reached the border between the U.S. and Canada. As the ice melted about 14,000 years ago, it changed the land. The melting ice carved out deep valleys and moved soil around. This process created the deep basins we see today.

These basins are filled with both salt and fresh water.

People have lived near these waters for a very long time. Native Americans have a special name for this place. They call it Whulge in the Lushootseed language. This name means "sea, salt water, ocean, or sound." In 1792, George Vancouver gave it a different name. He named it "Puget's Sound" to honor Peter Puget. Peter Puget was a lieutenant on the Vancouver Expedition.

Today, many big cities sit along the shore. These include Seattle, Tacoma, Olympia, and Everett.

The Sound is made of four deep basins. These are Hood Canal, Whidbey Basin, South Sound, and the Main Basin.

Shallow areas called sills sit between these basins. One important sill is at the Tacoma Narrows. The water is also very deep in some spots. The deepest part is off Jefferson Point. It reaches a depth of 920 feet. The main basin is also quite deep. It is about 1,000 feet deep between Whidbey Island and Tacoma. The tides move a huge amount of water every day.

Many living things thrive in these waters. You might see a harbor seal resting near the coast. Under the waves, there are many types of sea plants. Bull kelp and eelgrass grow in the water. These plants are very important for the ocean life here. You can also find fish like sockeye salmon.

The mix of fresh and salt water makes it a special home. It is a place where the mountains meet the sea.

Puget Sound is a complex estuarine system located on the northwest coast of Washington state. An estuary is a place where freshwater from rivers meets saltwater from the sea.

This system is part of the larger Salish Sea. The Salish Sea includes Puget Sound, the Strait of Georgia, and the Strait of Juan de Fuca. Puget Sound is the second-largest estuary in the United States. Only the Chesapeake Bay in Maryland and Virginia is larger. The Sound connects to the open Pacific Ocean through the Strait of Juan de Fuca. This connection happens through three main entrances. The largest is Admiralty Inlet. The other two are Deception Pass and the Swinomish Channel.

The geography of the Sound is defined by several deep basins. These basins are separated by shallower underwater ridges called sills. A sill is a submarine terminal moraine, which is a pile of debris left by a glacier. The four main basins are Hood Canal, Whidbey Basin, South Sound, and the Main Basin. The Main Basin is further divided into the Central Basin and Admiralty Inlet. Significant sills include the one at Admiralty Inlet and the one at the Tacoma Narrows. The Tacoma Narrows sill sits about 40 feet below the surface. These sills act as barriers that check the flow of water between the different basins.

Glacial activity shaped the landscape of the Sound millions of years ago. During the Vashon Glaciation, a massive ice sheet called the Puget Lobe covered the region. This ice was about 3,000 feet thick near Seattle. The ice reached almost to the current border between the U.S. and Canada. About 14,000 years ago, the ice began to retreat. As the glaciers melted, they eroded the land and created deep valleys. This process formed the fjord system of flooded glacial valleys we see today. The melting ice also left behind vast amounts of glacial till. This is a mixture of unsorted soil, gravel, and rocks.

As the ice retreated, several large lakes formed in the landscape. The first was Glacial Lake Russell, which stretched from Seattle to the Black Hills. Sediments from this lake created the Lawton Clay, a blue-gray clay. Later, Glacial Lake Bretz formed in the region. Eventually, the melting ice allowed marine waters to flood the lowlands. This created the modern Puget Sound. The weight of the massive ice sheets actually depressed the land. After the ice melted, the land began to rise again in a process called post-glacial rebound. Because the land rose at different rates than the sea level, the basin filled with both fresh and salt water.

The Sound is also shaped by tectonic forces. It sits part of the Cascadia subduction zone. This is a place where the Juan de Fuca Plate is being pushed under the North American Plate. This movement can cause earthquakes. A massive magnitude nine earthquake occurred on January 26, 1700. Today, smaller earthquakes still happen as oceanic rocks fracture under stress. The Seattle Fault and the Tacoma Fault also run through the region. These faults can cause the ground to buckle or shift.

The water in the Sound is a mix of salt and fresh water. Rivers from the Olympic and Cascade Mountains flow into the system. The mean annual river discharge is about 2,100 cubic feet per second. The tides in the Sound are of the mixed type. This means there are two high tides and two low tides each day. The tidal range increases as you move south. At Port Townsend, the difference between high and low water is about 14 feet. In Olympia, at the southern end, it increases to about 16 feet.

Many different species live in these waters. Marine plants like eelgrass and various types of kelp are very important. Bull kelp forms large canopies near the surface. These plants provide habitat for animals like the harbor seal. Many fish species also rely on the Sound. Sockeye salmon are a notable example of the life found here.

The complex mix of deep basins, flowing tides, and mountain runoff makes Puget Sound a unique maritime environment.