How Much of The Ocean Has Been Explored?

The ocean covers around 70% of the Earth’s surface. It’s the most livable area on Earth with more life in its waters than any other place on earth.

Take a look at the magnitude of the ocean. Its area is approximately 139 million square miles (360 million square kilometers) with an average of 12,080 feet (3,682 meters).

At the beginning of 2022, just 20% of the globe’s seafloor had been marked using the latest technologies. This included high resolution (multibeam sonar technology) typically attached to ships that provided a more detailed view of the seafloor resolution.

Even though more than half of the seafloor under US waters has been mapped to the latest standards, the seafloor left unmapped is greater than the land areas covering all fifty states, the District of Columbia, and the five US territories. Therefore, there’s an enormous amount of seafloor still to be mapped.

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NOAA Ocean Exploration

NOAA Ocean Exploration

Much of the information in this article would have been very difficult to collect and collate if this invaluable service did not exist. So, here’s to the boys and girls of the NOAA (National Oceanic and Atmospheric Administration) program and an acknowledgment to our federal government for funding them.

The only federal program devoted to studying our oceans is the NOAA Ocean Exploration program. It is designed to fill the huge gaps in our knowledge about America’s oceanic waters and the seafloors deep beneath. The NOAA Ocean Exploration program will deliver the necessary ocean data to improve our country’s security, health, and economy.

How NOAA explores the ocean

Utilizing the most modern tools and technologies, the NOAA Ocean Exploration investigates our deep ocean’s unexplored or under-studied regions. It makes discoveries that have scientific as well as economic and cultural worth.

Through the live streaming of data and video and online coverage, educational opportunities, and events, NOAA provides researchers, resource managers, students, the general public, and other people with ocean exploration experience.

This allows for greater participation in science, fosters and encourages a future generation of ocean explorers, and engages the general public in exploration activities.

Oceanic facts and figures

Ocean floor

Despite its significance, the vast majority of our oceans are mostly unexplored. Through exploration, we’re discovering more about its chemical, biological, physical, geological, and archeological aspects.

Exploration leads us to new superficial discoveries, but we need to draw a map before conducting a detailed exploration.

Mapping the ocean

Although the entire seafloor is recorded using data from satellites, the data offers only a broad view of the seafloor. There is a lack of detail in these maps, which means the most important features of the geography (like seamounts) and objects (like shipwrecks) are invisible.

Seafloor mapping gives a glimpse of what’s under the ocean’s surface and helps us make decisions about which areas to investigate further (e.g., using submersibles, such as remote-operated vehicles).

There is more information regarding the ocean floor than there is about the species that make the ocean their home. Seafloor maps give information on potential habitats, but they don’t reveal species living on the seafloor or within the water column.

They also don’t give information on how they interact with one another and their environment.

Scientists estimate that there could be between 700,000 to 1 million species of marine life (excluding the majority of microorganisms which may themselves number in many millions). Around two-thirds of the species, perhaps more, are yet to be identified or described formally, with nearly 2,000 new species being accepted by scientists each year.

Problems we face with mapping the ocean

Ocean creatures

Although we can assess how much of the ocean’s seafloor has been explored and the species that have been discovered and described, it’s difficult to quantify exactly how much ocean, including the seafloor and the water column, has been studied.

There is much more to discover about our oceans and their creatures. However, we are making progress. We are learning more every year. We continue to uncover new creatures and features that provide clues to our history and the resources that could enhance our lives in the future.

Yet we must be realistic. The ocean will never be explored to its fullest. Earth changes constantly, and it is crucial to comprehend these changes, given the significance of the ocean in our daily lives.

What’s the point of exploring the ocean?

Finding unusual things

The process of exploring the ocean is all about finding new things and identifying things that are unique and surprising. Exploring the ocean is how we gather the data needed to tackle both management requirements and emerging and current research.

Exploration ensures that ocean resources aren’t just managed but are managed sustainably and ensures that those resources will be there for the next generation to benefit from.

Exploration of the US Exclusive Economic Zone can be vital to national security. It allows us to define boundaries, safeguard American interests, and take advantage of ocean resources.

Ocean exploration data can assist us in understanding how we affect and are becoming affected by shifts to the Earth’s environment, which includes the changes in weather and climate. Understanding the secrets of ocean ecosystems may provide new sources of treatments and vaccines for medical conditions, food, energy, and much more.

It can also lead to the invention of products that mimic the characteristics of deep-sea mammals.

The insights gained from ocean exploration could aid us in understanding how we can react to tsunamis, earthquakes, and other risks.

Driving new technologies

ocean exploration

The difficulties encountered while exploring the ocean may be the catalyst for developing innovative technologies and engineering developments that can be used in other scenarios. For example, enabling us to be more effective when faced with any ocean disaster such as an oil leak.

Additionally, ocean exploration can enhance ocean literacy and motivate youngsters to pursue career options in engineering, science, technology, and math.

Tools of the trade: some of the equipment used to explore the ocean


It is estimated that the depth of the ocean is on average more than 2.23 miles (three thousand meters) and scientists need specific equipment capable of exploring these areas of intense cold and complete darkness. Over the past several years, underwater vehicle technology has been refined and developed, enabling us to see the ocean, sample it, and then survey deep-sea habitats on our planet.

Submersibles are underwater remote-controlled vehicles transported on ships to gather and record data from the ocean’s seafloor and water column for scientific analysis. There are three primary kinds of underwater vehicles, such as remotely operated vehicles, human-occupied vehicles, and autonomous underwater vehicles.

ROVs (remotely operated vehicles)

These underwater robots are secured and used for exploration, research, and collection of images within the water column and beneath the seafloor. Remotely operated vehicles are tied to the ship, allowing topside controllers to operate the undersea vehicles seamlessly in real-time.

A large number of ROVs can also retrieve samples using an arm manipulator controlled by a pilot. Later examination of these samples can provide more information about the sea.

HOVs (Human-occupied vehicles)

A small group of pilots and scientists go directly to the ocean floor for a short time. HOVs, like other submersibles, come outfitted with collection instruments, manipulator arms, light sensors, and cameras.

However, HOVs are outstanding in their capacity to provide scientists with an opportunity to see things with their own eyes and bring their expertise deep into thousands of feet under the water to observe, explore, take samples, observe, and conduct research in person.

AUVs (Autonomous underwater vehicles)

These robots are preprogrammed to glide, dive, or drift across the sea without manual operation by humans. AUVs gather high-resolution sensor data and provide precise information for researchers.

Once installed, AUVs operate on their own on a planned route, which allows researchers to conduct their own research while the autonomous underwater vehicle is studying the ocean’s surface or deep.

The use of sonar to explore the ocean

Sonar, or Sound Navigation and Ranging, is useful for mapping and exploring the ocean since sonar waves travel further in the water than radar or light waves. Scientists at NOAA mostly make use of sonar to develop nautical charts.

They also use sonar to find underwater hazards, for navigation, and to locate and map the positions of objects on the seafloor, such as shipwrecks.

There are two kinds of sonar: passive and active.

Active sonar

Active sonar

This type sends sound (acoustic) waves into the water. When an object falls into the path of outgoing sonar waves, it causes the acoustic wave to bounce back and returns the signal as an “echo”.

If the transducer has been equipped with the capability to receive signals, it will measure the intensity of that sound signal. By measuring the duration between the emission of an audio signal and the time it is received, the transducer can determine the direction and range of the target.

Passive sonar

These systems are used to detect the sound of ocean objects such as ships, submarines, or marine mammals like whales. Unlike active sonars that emit sound waves, passive sonar does not produce its own signals.

This benefits military ships that do not wish to be tracked and research missions that focus on silently “listening” to the ocean.

Passive sonar identifies only acoustic waves that head towards it. Passive sonars cannot determine the distance of an object when it is not used together with other devices for passive listening.

However, many passive sonar devices working together can triangulate and locate the source of sounds.

Multibeam echo sounders (MBES)

Similar to other systems based on sonar, MBEs emit acoustic waves and then evaluate any return signals (echoes) that bounce off underwater objects or the seafloor. Sonars with multiple beams release sound waves from beneath a ship’s hull to provide a fan-shaped signal covering a larger area of the seafloor.

They measure and track the amount of time it takes for the sound wave to be transmitted by the transducer towards the ocean floor (or an object) and then back towards the receiving device.

Multibeam sonars create a “swathe” of soundings to fully cover an area. The coverage area of the seafloor is determined by its depth in the water, which is typically between two and four times the depth of water.

Other clever equipment used in mapping the ocean

light detection and ranging

Lidar (light detection and ranging)

This technology determines the depth of an object by studying the reflection of laser light on it. Lidar surveys are generally equipped on aircraft and provide continuous, seamless coverage across the ocean and land.

Topographic laser scanners

Locates and measures characteristics like small islands, islets, and rocks. The laser head generates 16 laser beams that reflect off the object and are redirected back to the head of the laser.

The computer then utilizes this information in conjunction with precise positioning and position (roll and pitch as well as yaw) information to determine the size and location of the item.