A cabled observatory is a seabed

oceanographic Oceanography (), also known as oceanology, sea science, ocean science, and marine science, is the scientific study of the ocean, including its physics, chemistry, biology, and geology. It is an Earth science, which covers a wide range of top ...

research platform connected to land by cables that provide power and communication. Observatories are outfitted with a multitude of

scientific instruments A scientific instrument is a device or tool used for scientific purposes, including the study of both natural phenomena and theoretical research. History Historically, the definition of a scientific instrument has varied, based on usage, laws, an ...

that can collect many kinds of data from the

seafloor The seabed (also known as the seafloor, sea floor, ocean floor, and ocean bottom) is the bottom of the ocean. All floors of the ocean are known as seabeds. The structure of the seabed of the global ocean is governed by plate tectonics. Most of ...

and

water column The (oceanic) water column is a concept used in oceanography to describe the physical (temperature, salinity, light penetration) and chemical ( pH, dissolved oxygen, nutrient salts) characteristics of seawater at different depths for a defined ...

. By removing the limitations of undersea power sources and sonar or RF communications, cabled observatories allow persistent study of underwater phenomena. Data from these instruments is relayed to a land station and data networks, such as

Ocean Networks Canada Ocean Networks Canada is a world-leading research and ocean observing facility hosted and owned by the University of Victoria, and managed by the not-for profit ONC Society. ONC operates unparalleled observatories in the deep ocean and coastal ...

, in real time.

On-board sensors

Cabled observatories have the benefit of high-power cable connections that can support a variety of

instrumentation Instrumentation is a collective term for measuring instruments, used for indicating, measuring, and recording physical quantities. It is also a field of study about the art and science about making measurement instruments, involving the related ...

at any time. Such instrumentation can include cameras and microphones that can take high-definition audio and video, standard sensors that measure pressure, temperature, oxygen content, conductivity,

turbidity Turbidity is the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of both water clarity and wa ...

, and chlorophyll-a fluorescence, and custom sensors for specialized purposes. Over 200 instruments can be installed on a cabled observatory at a time, as seen on the

NEPTUNE Neptune is the eighth and farthest known planet from the Sun. It is the List of Solar System objects by size, fourth-largest planet in the Solar System by diameter, the third-most-massive planet, and the densest giant planet. It is 17 t ...

and

VENUS Venus is the second planet from the Sun. It is often called Earth's "twin" or "sister" planet for having almost the same size and mass, and the closest orbit to Earth's. While both are rocky planets, Venus has an atmosphere much thicker ...

observatories.

Comparison with other data collection methods

Cabled observatories are ideal for use in complex regions of the

ocean The ocean is the body of salt water that covers approximately 70.8% of Earth. The ocean is conventionally divided into large bodies of water, which are also referred to as ''oceans'' (the Pacific, Atlantic, Indian Ocean, Indian, Southern Ocean ...

where continuous data sampling is required for understanding the area of interest. Such areas include the complex biospheres of the temperate coasts and polar regions, which are sensitive to

climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...

. Conventional methods for oceanographic data collection, such as by ship, are often limited by the harsh typical weather conditions and cannot sample data continuously. Mooring systems have also been a common method for long-term ocean data sampling, however they require scientific cruises for scientists to receive data or to discover damage to the mooring system and carry out repairs. Data collection by ship and by mooring system in complex or harsh environments has historically led to data losses and inaccurate conclusions. By eliminating the need for regular ship use and bolstered with extensive sensor sets, enabled by direct power connections, cabled observatories have the capability to provide continuous and detailed data sampling for regions of the ocean that are otherwise inaccessible.

Usage locations

Cabled observatories are permanently fixed in one area and cannot take measurements beyond that area, however they can support sensors and apparatuses that can travel vertically in the

and observatory data can be combined with ship data to create a more complete understanding of the area as well. An observatory can be placed as far as 300 km from shore if the conditions permit. Observatories can be placed in waters as deep as 2500 meters and as shallow as 10 meters, even when the wave height is greater than the water depth.

Operation Limitations

Many issues involving data reliability and loss have arisen and been investigated by teams running cabled observatories. Such issues include data loss, sensor failure, and data reliability issues. The sources of these issues are diverse, with common causes being improper operation,

biofouling Biofouling or biological fouling is the accumulation of microorganisms, plants, algae, or small animals where it is not wanted on surfaces such as ship and submarine hulls, devices such as water inlets, pipework, grates, ponds, and rivers that ...

, cable connection issues, and leakages. Systematic improvements, to lessen the impacts of such factors, are currently being studied by groups such as

. Additionally, data loss can occur from improper installation or operations of sensors and data management, which are more likely to occur if those responsibilities are taken on by research groups external to the observatory team. This issue prompted the usage of streaming of final probe data to communicate data to partner research groups for the COSYNA observatory team, and streaming is now a common method for data communication for other observatory teams.

Examples of cabled observatories

MARS Mars is the fourth planet from the Sun. It is also known as the "Red Planet", because of its orange-red appearance. Mars is a desert-like rocky planet with a tenuous carbon dioxide () atmosphere. At the average surface level the atmosph ...

(Monterey Accelerated Research System) *

(North-East Pacific Time-series Undersea Networked Experiments) *

(Victoria Experimental Network Under the Sea) * Liquid Jungle Lab (LJL) Panama- PLUTO * (Hawaii-2 Observatory)- early experimen

*ALOH

*ESONET *

Ocean Observatories Initiative The Ocean Observatories Initiative (OOI) is a National Science Foundation, National Science Foundation (NSF)]Major Research Facilitycomposed of a network of science-driven Ocean observations, ocean observing platforms and sensors (ocean observato ...

Cabled Array *Exploration & Remote Instrumentation by Students (ERIS)

References