Seventy-one per cent of the world’s surface is water – a vast blue expanse of rolling waves full to the brim with countless animal and plant species. But few people consider just how huge the oceans are beneath the surface.
In February 2018, the maritime and scientific communities announced their ambitious plans to map the Earth’s entire ocean floor by 2030. This project, Seabed 2030, is headed up by General Bathymetric Chart of the Oceans (GEBCO) and Japanese NGO, the Nippon Foundation. Considering that over 80 per cent of the ocean floors either haven’t been visualised at all, or have only been poorly imaged using old techniques, mapping this huge expanse in the space of 12 years is no mean feat.
Over the years, many techniques have been used to survey the oceans. The earliest methods of depth measurement were recorded in tomb paintings of ancient Egypt dating from 1800 B.C., where depictions show a man using a long slender pole to measure water depths. Deeper waters could be measured by casting a weighted line off the side of the ship and recording how much string was immersed when the weight met the ocean floor. Similar systems were used on the voyage of HMS Challenger in the 1870s – wires and a winch allowed greater depth measurements but, to achieve good accuracy, this was a very slow process. At the beginning of the 20th century, basic sonar systems were developed. If you could measure the time it takes for a reflected ping to be heard and know the speed of sound in water, then you can derive the water depth. These efforts provided the first insight into seafloor morphology. In 1957, Marie Tharp and Bruce Charles Heezen created the first three-dimensional physiographic map of the world’s ocean basins. Around this time, the development of computers allowed improvements in research efficiency and analysis of large quantities of data. This led to the creation of the first digital map of the world ocean bed in 1970.
Constant developments in technology has led us to the modern techniques that we use today. Multibeam echosounders work in a similar way to the early sonar systems but these emit sound waves in a fan shape beneath a ship’s hull – measuring whole areas at once. LIDAR systems are also used which use laser lights instead of sound to measure distances underwater.
According to the Seabed 2030 Project, 32 million square kilometres of the ocean has been mapped – whilst this seems a lot, this is actually only 15 per cent of the Earth’s oceans. This global initiative aims to create a detailed, freely available map of the entire ocean floor by the year 2030 – a much-needed resource in modern ocean science. This will be a collaborative effort from 100 organisations which formally support this initiative. The project will be a key feature of the recently announced United Nations Decade of Ocean Science initiative that will begin in 2021. “While mapping the entire ocean floor by 2030 seems like a daunting task, we are making headway thanks to the commitment of commercial, scientific and private vessels,” said Seabed 2030 Director, Jamie McMichael-Phillips.
One of the most exciting efforts into ocean mapping is by Schmidt Ocean Infinity. The company was launched in 2016 and have announced their latest fleet of 11 robotic boats in February 2020. The ‘Armada’ are the vessels that they hope to use to map the entirety of Earth’s oceans over the next 10 years. Uncrewed Surface Vessels (USV) are the latest technology which open up the possibility for long-term marine missions. Ocean Infinity’s USVs range from 21 to 37 metres long and are each fitted with hull-mounted, multi-beam echo-sounders designed to provide a radar image of the sea floor. They will also have their own capability to deploy tethered robots to inspect all the way down to the floor of the ocean – up to 6,000 meters below the surface. Whilst surveying the ocean floors, the boats will also be used to carry cargo in places like the North Sea, running containers out to oil and gas platforms. Ocean Institute have previously used their other vessels to find wreckages and have contributed to the search for the missing Malaysian Airlines MH370 flight in a ‘no find, no fee’ mission. This new fleet will be powered by diesel electric and have reduced CO2 emissions compared to regular boats. Whilst some have raised concerns similar to those of driverless cars about the unmanned boats, many believe that USVs are a huge step in the right direction towards effective ocean surveying.
But why is ocean mapping important? Ocean Institute co-founder, Wendy Schmidt, highlights how the ocean is so much more than the blue waves we see at the surface: “Picture huge mountains and canyons, exotic hydrothermal vent forests and unique conditions that mimic other planets…There are still so many things we do not know about the topography or the ecosystems that cover the largest part of our earth.” Beneath the surface are potentially millions of unknown species to uncover, all of which have their own individual contributions that they make to both ocean and human health without our knowledge. Schmidt Ocean Institute will be making a vital contribution to the Seabed 2030 project, ultimately allowing the creation of a high-resolution map of the seafloor, an invaluable tool in protecting our oceans.