Marine technology uncovers the secrets of our oceans
by Matt Hodson, Operations Director, Marine Hub Cornwall
22 | Feb | 2018
Despite the fact that the oceans cover more than 70% of our Earth, only a small proportion of them have been explored in detail beneath the surface. Some experts put the figure for this as low as 5%. However, as marine technology advances, we are able to employ a wide variety of techniques to fill this gap in our knowledge and to paint a much more detailed picture of the unique world that exists in our deep oceans. This is creating important new work for surveying companies and the technology businesses that design their equipment. It is also helping to create new markets and new ways of working in our seas.
Remotely Operated Vehicles and Autonomous Vehicles are allowing us to map the oceans in new ways, using the latest sensor and data collection technologies. Autonomous Vehicles can operate below the surface and can stay at sea for extended periods of time – months if necessary.
Floating instruments such as buoys are able to gather valuable data on sea conditions, including temperature, waves and wind. Free-floating buoys can be released by ships and transmit data on ocean currents and the characteristics of the seawater in different locations.
Satellite observations have played a growing role in our increased understanding of the oceans. Satellite imagery has greatly increased our understanding of ocean currents and weather systems such as storms and hurricanes. Thermal imagery has allowed us to learn more about the temperature of the seas. Satellites have also generated new information about natural phenomena like coral reefs.
Some oceanographers have even employed the help of marine life to gather new data. Animals including whales, seals and sharks have been fitted with sensors and tracking devices. These have been used to send back data from areas that might otherwise be inaccessible to marine technology, as well as revealing new information about the movement patterns of sea creatures.
Older technologies also have an important part to play. The basic principles of SONAR were developed over 100 years ago. Modern, sophisticated SONAR devices have been very successful at measuring water depth and mapping the seabed accurately. Ships fitted with powerful SONAR equipment can scan very large areas of the seafloor.
To understand the composition of the seabed, grabbing devices can be deployed from moving ships and operate to a depth of up to 200 metres. These rapidly gather small samples of the material on the surface of the seabed. For more thorough exploration of the seabed, deep sea drilling ships can employ hydraulic piston corers. These can be used to obtain core lengths of up to 200 metres in depth. Then after the core is removed, cameras and other sensors can be lowered into the core hole to study the geological properties deep below the surface.
Towards the end of 2017, a team of scientists from New Zealand successfully drilled through the Ross Ice Shelf. This is the largest ice shelf in Antarctica, covering an area as large as Spain and with ice over 300 metres thick. They were able to lower sensors and take detailed readings of the ocean that exists beneath the ice – one that contains a similar volume of water to the North Sea and could have a major influence on the temperature of the southern oceans.
All of the above marine technology and the information it gathers can be combined with powerful software and Big Data applications to produce highly detailed maps of the topography under the oceans. The way in which our knowledge is growing can be illustrated by three relatively recent discoveries:
- A mostly submerged landmass called Zealandia has been mapped and some scientists now believe this to be a distinct continent in its own right. Zealandia sank after breaking away from what is now Australia over 60 million years ago. It covers nearly 2 million square miles and has unique geological characteristics that would support the theory of it being a separate continent.
- We now know a lot more about the hydrothermal vents that exist at the bottom of our deep oceans – the equivalent of hot springs on the seabed. These are supporting complex ecosystems of marine life, some of which are previously unknown species.
- There are very rich deposits of precious metals and minerals on the seabed. It is estimated that the amount of gold on the seafloor could be worth as much as 150 trillion dollars. An undersea mountain in the Canary Islands region has been mapped and found to be extremely rich in tellurium, a rare metal that is used in new technologies such as solar cells. This one deposit is thought to contain this metal in concentrations 50,000 times higher than those found on the land. Other seafloor locations around the globe have been shown to contain diamonds, silver, copper, zinc, manganese and cobalt.
This last development demonstrates how our improved exploration of the seas is creating startling new opportunities for marine technology businesses. Deep sea mining is poised for huge growth over the next 20 years and will need careful planning and control. It is more important than ever that new commercial developments are carried out responsibly, so that we minimise the impact on the natural environment. In this way, we can ensure that we realise the full potential of this industrial revolution on our seas.