Today’s technologies allow us to explore the ocean in increasingly systematic, scientific, and noninvasive ways. With continuing scientific and technological advances, our ability to observe the ocean environment and its resident creatures is beginning to catch up with our imaginations, expanding our understanding and appreciation of this still largely unexplored realm.
This section highlights some of the technologies that make exploration possible today and the scientific achievements that result from this exploration. Technologies include platforms such as vessels and submersibles, observing systems and sensors, communication technologies, and diving technologies that transport us across ocean waters and into the depths and allow us to scientifically examine, record, and analyze the mysteries of the ocean.
Acoustic Doppler Current Profiler
The Acoustic Doppler Current Profiler (ADCP) measures the speed and direction of ocean currents using the principle of “Doppler shift”.
Autonomous Underwater Vehicles (AUVs)
Autonomous underwater vehicles, or AUVs, are independent underwater robots used to explore our ocean.
CTD stands for conductivity, temperature, and depth, and refers to a package of electronic devices used to detect how the conductivity and temperature of water changes relative to depth.
Using devices known as drifters, scientists can study the complexities of global ocean currents, and, in turn, the many systems that they influence. With advances in technology, drifters now provide researchers with information about ocean circulation patterns in real time.
Environmental DNA (eDNA)
Environmental DNA (eDNA) is the genetic material shed by organisms in the water column. By collecting samples of mucus, feces, or tissue particles, scientists can process eDNA to make new discoveries about marine life.
A magnetometer is a passive instrument that measures changes in the Earth’s magnetic field.
Geographic Information System (GIS)
A geographic information system, or GIS, is a computer-based conceptualized framework used for organizing and analyzing data related to positions on Earth’s surface.
Human-occupied Vehicles (HOVs)
HOVs are submersibles that bring a small group of scientists, pilots, and electronic equipment down in the water column and onto the seafloor, allowing in-person research and observation.
Geographic information systems (GIS) are mapping tools that can essentially create a virtual ocean inside of a computer. GIS components work together as a system to provide a digital platform for viewing and processing layers of spatial information.
Satellites that detect and observe different characteristics and features of the Earth's atmosphere, lands, and ocean are often referred to as environmental satellites. Most environmental satellites have one of two types of orbits: geosynchronous or sun-synchronous.
SOund NAvigation and Ranging—SONAR—is used to find and identify objects in water. It is also used to determine water depth (bathymetry). Sonar is applied to water-based activities because sound waves attenuate (taper off) less in water as they travel than do radar and light waves.
Multibeam bathymetry collected during Leg 1 of the Windows to the Deep 2019 expedition offshore the southeastern United States revealed several interesting features that were investigated via remotely operated vehicle exploration during Leg 2 of the expedition. Image courtesy of the NOAA Office of Ocean Exploration and Research, Windows to the Deep 2019.
Remotely Operated Vehicles (ROVs)
Remotely operated vehicles, or ROVs, are submersible robots that allow us to explore the ocean without actually being in the ocean.
Side Scan Sonar
Side scan sonar is a category of active sonar system for detecting and imaging objects on the seafloor. The multiple physical sensors of the sonar — called a transducer array — send and receive the acoustic pulses that help map the seafloor or detect other objects. This array can be mounted on the ship’s hull or placed on another platform like a towfish.
Split-beam sonar is a type of active sonar that uses sound to explore the composition of our ocean. Whether attached to the hull of a ship, a pole mount, an autonomous underwater vehicle, a water column profiling system, or even stationary on the seafloor, this machine works by emitting a single vertical sound pulse called a “ping” at a specific frequency, then listening for the echo’s return.
Synthetic Aperture Sonar (SAS)
Synthetic aperture sonar (SAS) is an emerging type of sonar that uses an artificial, or synthetic, array to capture high-resolution images. SAS can be used for imaging cultural heritage sites like shipwrecks, classifying habitat or biological organisms, and characterizing seafloor sediment makeup.
Darkness, cold, and crushing pressures have challenged the most experienced engineers to develop submersibles that descend to seafloor depths that are not safe for divers, allowing us to explore the deep ocean firsthand.
Many components make up a successful research submersible. The suction sampler and detrital sampler were designed to attach to different types of submersibles and collect many of the unique and fragile organisms found only in the deep ocean.
Technical diving is a term used to describe all diving methods that exceed the limits imposed on depth and/or immersion time for recreational scuba diving. Technical diving often involves the use of special gas mixtures (other than compressed air) for breathing.
Technologies for Ocean Acoustic Monitoring
Just as microphones collect sound in the air, underwater hydrophones detect acoustic signals, or sounds in the ocean, including marine mammals, earthquakes, ships and waves.
Telepresence is the concept of providing an individual or group of individuals with the data and information necessary for participation in an event or effort live when those individuals are not physically present for the event.
Trawls, which are nets towed behind a boat to collect organisms, have been used by fishermen for centuries. Trawls are used to collect quantitative data of marine organisms, such as biomass, length and weight, and age class distributions.
From onboard equipment to collect weather and ocean information to divers, submersibles, and other observations deployed from a ship, vessels are arguably the most critical tool for scientists when it comes to exploring the ocean.
XBTs (Expendable Bathythermographs)
Expendable bathythermographs, or XBTs, are small torpedo-shaped probes used to collect ocean temperature data. After being deployed from a vessel with a launcher, the XBT probe falls through the water column at a predictable rate of descent, measuring the ocean’s temperature and transmitting the data back to the surface.