Posted on June 28, 2023
The ocean is a beautiful, dynamic, and sometimes dangerous place. Unsurprisingly, this is why a lot of USGS researchers spend their entire careers studying it. In celebration of National Ocean Month, we thought it would be a good time to dive in and feature ten ocean field sites you’ve got to “sea” to believe.
1. Juan de Fuca Canyon, Washington State
Located off the coast of Washington, Juan de Fuca Canyon is a steep, narrow submarine canyon that plunges southwest from the continental shelf down to the Pacific Ocean seafloor. At its base is the Cascadia megathrust fault, an area where the Juan de Fuca Plate slides beneath the North American Plate. This confluence, known as the Cascadia Subduction Zone, has been responsible for some of the largest earthquakes on Earth, including a magnitude 9 quake on January 26, 1700. The USGS continues to advance subduction zone science and improve hazard assessments by using cutting-edge seafloor scanning technology and onsite sampling to characterize this offshore environment.
DID YOU KNOW:
The canyon’s namesake – Strait of Juan de Fuca – was named after the Greek sailor Ioannis Phokas, who explored the west coast of North America in the 16th century for Spain using the name Juan de Fuca.
2. Vailulu’u seamount, American Samoa
The youngest and most active volcano of the American Samoan Islands, Vailulu’u has erupted at least three times since the 1970s. In 2005, a new 1,000-foot-tall volcanic cone named Nafanua was discovered within its crater. Currently, Vailulu’u remains nearly 2,000 feet below the ocean’s surface, so it could take decades before it becomes a full-fledged island. Recent earthquake activity in American Samoa, particularly beneath Taʻū Island, led USGS scientists to set up a new volcano monitoring network on the islands and served as a reminder that these volcanoes remain active today.
DID YOU KNOW:
The Samoan Islands formed as the Pacific plate moved over a volcanic hotspot, similar to how the Hawaiian Islands were created.
3. Cape Hatteras, North Carolina
Cape Hatteras National Seashore accounts for over half of the 125-mile stretch of barrier islands that make up the Outer Banks and is separated from the North Carolina mainland by Pamlico Sound. Like all of the islands that make up the Outer Banks, Cape Hatteras is in constant flux. It is continually being reshaped by environmental and human forces, including sea-level change, storms, and construction and development. USGS scientists have been working to understand the factors that control coastline changes and to assess the risks that storms and changing sea levels may pose in the future.
DID YOU KNOW:
Storms, shallow water, and shifting sandbars have sunk over 1,000 ships off Cape Hatteras since 1600, giving this area the nickname the “graveyard of the Atlantic.”
4. Buck Island Reef National Monument, U.S. Virgin Islands
Buck Island Reef National Monument is a culturally and ecologically important location in St. Croix, U.S. Virgin Islands. Like many coral reefs in the western Atlantic Ocean, the USGS has observed that Buck Island has begun seeing its reefs shrink in recent decades. The island’s beaches provide habitat for several threatened and endangered species like sea turtles and the St. Croix ground lizard and serve as nesting habitat for migratory shorebirds. In addition to its ecological diversity, the park’s rich history was also instrumental in the decision to make it the first marine protected area in the United States.
DID YOU KNOW:
President John F. Kennedy referred to the Buck Island Reefs as “one of the finest marine gardens in the Caribbean Sea.”
5. Escanaba Trough, California
Located along the Mendocino Fault Zone off the coast of California, the Escanaba Trough makes this list because it is the only mid-ocean spreading area located within the U.S. Exclusive Economic Zone, a part of the Pacific Ocean where the U.S. has exclusive rights to extract natural resources. Two miles below the ocean’s surface as the seafloor spreads, new oceanic crust pushes up from Earth’s mantle to be met with blankets of thick sediment, frigid temperatures, and complete darkness. The combination of sediments and hydrothermal fluids has resulted in a unique hydrothermal system that potentially contains deposits of economically important minerals, including gold, silver, copper, zinc, and lead.
DID YOU KNOW:
The name Escanaba comes from an Ojibwa/Chippewa term meaning either “flat rock” or “land of the red buck.” A ship with that namesake discovered the submarine trench off the northern California coast in 1950. Subsequent scientific expeditions referred to this seafloor spreading area as Escanaba Trough, and the name stuck.
6. Chesapeake Bay Crater, Virginia
Unlike all the other field sites on this list, the Chesapeake Bay meteorite impact site is the only one from out of this world. About 35 million years ago a meteoroid 2-3 miles wide streaked through the Earth’s atmosphere and blasted an enormous crater into the continental shelf in what’s modern-day Virginia. The ancient impact was eventually buried beneath 1,000 to 1,500 feet of rocky debris, sediment, and marine deposits. The rivers of the Chesapeake region converged over the buried crater, helping shape the Chesapeake Bay. Surprisingly, people didn’t know the crater existed until the USGS and its international partners discovered it in the late 1990s.
DID YOU KNOW:
There are many different types of objects floating around space and depending on what they are made of and what they do, they are called different things. For example, a comet is made of ice and dust. An asteroid is made of rock or metal. A meteoroid is a small piece of an asteroid or comet. If a meteoroid enters the Earth’s atmosphere and burns up, it’s called a meteor (i.e., a shooting star). If the object reaches the ground, it is referred to as a meteorite.
7. Nantucket Sound, Massachusetts
The Nantucket Sound is located between Cape Cod and the islands of Martha’s Vineyard and Nantucket off the coast of Massachusetts. This part of the Atlantic Coast is extremely sandy, with large and mobile sand waves covering much of the seafloor. These shallow coastal waters provide important fishing grounds, habitat, and ample recreational and commercial opportunities. In addition, this area is essential for bringing electricity ashore for the Nation’s first large-scale offshore wind farms. Mapping the seafloor helps inform decisions about how to support different uses, and provides insights into historical changes in sea level, identifies safe and sustainable sand resources, and aids in our understanding of how the coastline evolves.
DID YOU KNOW:
Looking eastward from Martha’s Vineyard, the daily sunrise plays a prominent role in the spirituality of the Wampanoag Tribe (“People of the First Light”).
8. Norfolk Canyon, Virginia
Norfolk Canyon is a submarine valley that dips off the continental shelf near the coast of Virginia and serves as an interesting location for an amazing discovery that scientists never expected. In 2012, USGS researchers found methane bubbling up from the Atlantic Ocean seafloor. The methane seeps represent a new source of global methane not previously accounted for in this area. Most seeps are too deep for the methane to directly reach the atmosphere, so it remains in the water column. This methane activity contributes to a vast and diverse ecosystem. The Atlantic margin is home to hundreds of these widely distributed seeps that support these unique communities.
DID YOU KNOW:
Methane is a gas made up of molecules of carbon and hydrogen. It is produced either through the biologic decomposition of organic matter at shallow depths or it can be derived over millions of years by high-pressure and high-temperature processes that produce fossil fuels deep underground.
9. Dangerous Passage, Alaska
Dangerous Passage is a glacial marine fjord in western Prince William Sound, Alaska. In 1964, it was the site of one of the most tragic disasters in Alaska history. On March 27, a magnitude 9.2 earthquake struck, devastating the state and sending tsunamis across the Pacific Ocean. One place impacted the most was the village of Chenega, where a tsunami killed 23 of the 75 inhabitants. The devastating tsunami originated in Dangerous Passage, as a submarine landslide sent roughly 600,000 acre-feet of sediment sliding down a 425-foot slope, pushing a massive wave of water toward the village. The source of the fatal tsunami had been a mystery until USGS and their partners discovered its remnants in 2014.
DID YOU KNOW:
Tsunami travel time modeling indicates that the submarine landslide-generated tsunami struck the village of Chenega roughly four minutes after the earthquake shaking began.
10. Continental Slope, Northern Gulf of Mexico
The Continental Slope dips from the coast of Louisiana deep into the Gulf of Mexico. Starting in 2008, USGS scientists began deploying equipment in the Gulf to better understand Earth’s climate history. The key instrument is a sediment trap used to capture small particles floating through the water column. The traps are placed here because of the Gulf’s influence on climate — not just in North America, but globally. The water temperature is tightly linked to rainfall patterns in the U.S., as well as controlling how intense hurricanes become along the southeastern coast of the United States. This region also receives a huge amount of runoff from the Mississippi River, so measuring conditions here can inform us about links between land and marine climate.
Sources/Usage: Public Domain. Retrieving sediment trap used to study sediment flux in the Gulf of Mexico.
DID YOU KNOW:
Foraminifera, or forams, are single-celled microscopic, shelled organisms smaller than the tip of a pencil. They have been on Earth since before the dinosaurs and their shells can hold the key to understanding how our planet’s climate has changed. Foram shells absorb and retain information from their environment like ocean chemistry, temperature, and salinity. They only live for only a few weeks before dying and accumulating on the seafloor. The layering of sediment and forams creates a detailed record of environmental change that scientists examine for a peek back at history.
