What is marine geology?

Geology is the study of the Earth. This includes how the Earth was formed, how the Earth has changed since it was formed, the materials that make up the Earth, and the processes that act on it. Marine Geology focuses on areas affected by our oceans including the deep ocean floor, the shallower slopes and shelves that surround the continents, and coastal areas like beaches and estuaries. USGS marine geologists also study some coastal river areas and some large lakes.

More than half of our nation's population lives within 50 miles of the coast. Healthy coastal and offshore resources are vital to our nation's economy. The USGS studies coastal change, hazards that impact coastal areas, ocean resources, and coastal and marine ecosystems.

Learn more: Coastal and Marine Hazards and Resources Program

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Why are coral reefs in peril and what is being done to protect them?

Coral reefs can be damaged by natural processes, such as storms, but they are increasingly at risk from human activities. Oil spills and pollutants can threaten entire reefs. Excessive nutrients from land sources, such as sewage and agricultural fertilizers, promote the growth of algae that can smother corals. Other organisms harmful to corals,...

Where can I find bathymetric data?

The USGS has made bathymetric surveys for many coastal areas and for selected rivers and lakes in the U.S., including Yellowstone Lake, Crater Lake, and Lake Tahoe. Information and data for those studies is on the USGS Maps of America's Submerged Lands website. NOAA (National Oceanic and Atmospheric Administration) is the primary source of...

Where can I get current sea-surface temperature data?

The USGS has studied sea-surface temperature in many areas around the globe; you can find publications from these studies i n the USGS Publications Warehouse and by searching on the Internet. World maps and data are available from other agencies, particularly at the NOAA's Sea Surface Temperature , and at the JPL Physical Oceanography Distributed...

Why is the ocean salty?

Oceans cover about 70 percent of the Earth's surface and about 97 percent of all water on and in the Earth is saline —there's a lot of salty water on our planet. By some estimates, if the salt in the ocean could be removed and spread evenly over the Earth’s land surface it would form a layer more than 500 feet (166 meters) thick, about the height...
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Date published: June 21, 2019

Celebrate Oceans Month – USGS Science on the Seas

Our Earth is indeed a watery planet – nearly two-thirds of its surface is covered by water. And all but 3% of that water covers land submerged under the oceans. Our seas are the source of living and non-living resources that we rely on for food, recreation, protection from storms, energy and minerals, and so much more.

Date published: September 13, 2017

Federal Ocean Partnership Launches DEEP SEARCH Study of Coral, Canyons, and Seeps Off the Mid- and South Atlantic Coast

Scientists beginning a three-week research cruises to study deep-sea corals, canyons and seeps departed from Norfolk, Virginia on September 12 after a one-day delay due to the effects of Hurricane Irma. USGS research oceanographer Amanda Demopoulos is the lead scientist for this cruise, the first of three planned as part of a four-and-a-half year study.

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April 22, 2021

We are the Coastal and Marine Hazards and Resources Program

We are the USGS Coastal and Marine Hazards and Resources Program. Our mission is to provide science for sustainable stewardship of Earth’s precious resources. We conduct research, quantify resources, work to understand ecosystems, and develop tools to ensure our Nation has the best information to manage resources and prepare for

March 24, 2016

Marine Terraces of California: Landscapes from the Waves

  • Did you know soils on California’s marine terraces can be over a million years old? 
  • Have you wondered why California’s rugged shorelines are terraced?
  • Soils on marine terraces aid our understanding of soil formation, water movement, and carbon transformations under changing climate.
June 26, 2014

PubTalk 6/2014 — Into the Abyss

Living Without Light

by Nancy Prouty, Research Oceanographer 


  • As archives of natural and human activities, deep-sea corals are windows to the past.
  • Scientific studies of these slow-growing and long-living animals lead to good stewardship for healthy ecosystems.
  • Deep-sea coral communities are
June 28, 2012

PubTalk 6/2012 — Scanning the Seafloor with Sound

--modern sonar reveals hidden hazards and resources

by David Finlayson, Marine Geologist 


  • The USGS seafloor mapping program supports scientific studies across most marine disciplines, including geologic mapping, mineral exploration and environmental characterization.
  • See dramatic, colorful imagery of
Image: Geologists Search for Evidence of Ancient Beach Deposits and Uplifted Shorelines on Simeonof Island
August 9, 2011

Geologists Search for Evidence of Ancient Beach Deposits and Uplifted Shorelines on Simeonof Island

Scientists from the USGS, University of Rhode Island, and the Alaska Dept of Geological and Geophysical Surveys dig into coastal bluffs of Simeonof Island in search of evidence for ancient beach deposits and tectonically uplifted shorelines.

August 9, 2011

Ocean Acidification: Research on Top of the World

The Arctic Ocean is one of the most unique bodies of water on the planet. It houses large charismatic predators like polar bears, whales, and seals; critical species like shell fish and phytoplankton; and an array of organisms found nowhere else on Earth. The Arctic Ocean is also the most inaccessible and least explored ocean. Its remoteness has kept it ecologically

June 30, 2011

PubTalk 6/2011 — Exploring California's Amazing Seafloor

--the visionary California Seafloor Mapping Program

by Sam Johnson, USGS Pacific Coastal & Marine Science Center 


February 24, 2011

PubTalk 2/2011 — Is Our Coast in Jeopardy?

-predicting the impact of extreme storms on the California Coast

By Patrick Barnard, USGS Pacific Coastal & Marine Science Center


  • Extreme storms are expected to become more frequent and intense as a result of climate change
  • The USGS has developed the Coastal Storm Modeling System (CoSMoS) for predicting
Image: Puget Sound Seafloor
May 7, 2009

Puget Sound Seafloor

This photograph is of the Puget Sound seafloor and shows an area mixed with mud, gravel and cobble that is occupied by bivalve molluscs with exposed siphons, a sea star and metridium. This image was collected as part of USGS efforts to help with rockfish recovery in the Puget Sound. Scientists are mapping their ecosystem and habitat to understand population

Image: Rhode Island Seafloor
November 13, 2008

Rhode Island Seafloor

This photograph is of the seafloor on the Rhode Island coast and shows a skate on a fine-grained, likely silty or muddy seafloor. This photograph was collected to support research and management activities (e.g., wind farms and fisheries) along the Rhode Island inner continental shelf.

Image: Massachusetts Seafloor
September 9, 2007

Massachusetts Seafloor

This photograph is of the seafloor off the Massachusetts coast and shows sea stars, blood stars, blood drop tunicates, mussels and barnacles on cobbles and boulders covered with bubblegum algae and red filamentous algae. This photograph was collected as part of USGS research in collaboration with the Massachusetts Office of Coastal Zone Management to support