For many years, scientists have known more about the Moon’s surface than the depths of our planet’s oceans. The ocean bed has been one of the most unexplored areas on our planet because of its vast expanse of water. However, scientists and researchers from NASA and other institutions have now rewritten history with an incredible achievement: charting the ocean bed from outer space! Scientists have used satellite technology and an ingenious method of gravity to create detailed maps of underwater mountains, ridges, and trenches that were hitherto impossible to identify.
How NASA mapped the seafloor from space
The breakthrough comes from satellite altimetry, a technique that uses satellite data to measure the height of the ocean’s surface.The surface of the ocean, at a glance, looks flat, but in reality, it has small bumps and dips due to gravity.According to the NASA Earth Observatory, scientists were able to analyze the data from satellites like CryoSat-2 and Jason-1 to create a picture of the seafloor.Here’s how it works:
- The mountains and ridges on the seafloor have more mass
- The more mass, the greater the gravitational pull
- The water above the mountains and ridges will rise, creating small “bumps”
- The satellite can then detect the small changes in the height of the ocean’s surface
According to NASA, “mountains and other seafloor features… exert a gravitational pull on the water above, allowing scientists to map what’s below the surface.”
Why is this technique so ingenious
Mapping the ocean floor directly is an incredibly difficult task. Not only can light not travel in such deep water, but sonar mapping requires physical travel over such an extensive area. In fact, only a small percentage of the ocean floor has been mapped in this way.NASA explains that only “5 to 15 per cent of the global ocean floor” has been mapped in detail by ship sonar.This is where this satellite method becomes revolutionary:
- It is used over almost the entire globe
- It is faster
- It shows unknown features
Using satellite information gathered over decades of time combined with modern computer capabilities, scientists have been able to create maps that are “two to four times more detailed than before.”
What scientists discovered beneath the ocean
The new seafloor maps have revealed thousands of hidden geological features, including:
- Seamounts (underwater volcanoes)
- Abyssal hills (small rolling hills)
- Deep ocean trenches
These are not only interesting to look at, but they are also crucial to our understanding of the history of the Earth. Dietmar Müller, a geophysicist, says, “Detailed maps of the seafloor are a powerful tool for reconstructing the movement of tectonic plates and the formation of ocean basins.”In simple terms, the ocean floor is like a history book of how the continents have moved over millions of years.
Why seafloor mapping matters
The real-life applications of the NASA method of mapping the seafloor include:
- Navigation – to ensure the safe passage of ships and submarines.
- Infrastructure – to lay cables.
- Resource exploration – to locate new resources of minerals and energy.
- Climate – to understand the workings of the ocean.
Recent expeditions, including those sponsored by NASA using advanced satellite technology, are further improving the maps and filling in the gaps to give us an even more complete picture of the underwater world.The gravity-based method of seafloor mapping by NASA is a brilliant example of how technology can help us transcend the limitations of nature. By sensing small changes in the seafloor, scientists have succeeded in discovering the secrets that lie deep within the ocean.It also shows us that we do not always have to go deep into the ocean to explore it; at times, we have to look at it from above.