To Uncover an Ocean
It takes determination, bathymetry, and a whole lot of girl talk.
About the Author
Hi! My name is Gabriella, and, at the time of this piece, I am a sophomore in college.
I joined this year's cohort of the Girl Talk program simply because I had never heard of bathymetry. To commemorate all that Girl Talk taught me, I've created this StoryMap.
Please enjoy and immerse yourself in the world of mapping the seafloor.
Map the Seafloor?
For centuries, scientists asked this same question and thought they had the answer: there was no reason!
There were no mountains like in China...
...no volcanoes like in Hawaii...
...and no valleys like in Switzerland.
No one believed that the seafloor is just like the surface of the Earth.
The seafloor was just a flat, boring surface. In the words of a famous oceanographer:
The whole world was spread out before me. I had a blank canvas to fill with extraordinary possibilities, a fascinating jigsaw puzzle to piece together: mapping the world’s vast hidden seafloor.
So, she spread her map over the Atlantic...and proved them all wrong.
The Pioneer of Oceanography
The words in the last section were uttered by this woman. Her name was Marie Tharp.
Her path didn't start in science; she actually studied English and music in college. Being a woman in the 1950s meant that her career choices were slim.
However, World War II left many positions in science held by men vacant. Tharp seized the opportunity and worked at the Lamont Lab at Columbia University in NYC.
Despite initially not being able to board ships to collect data, she worked with Bruce Heezen to produce the first map of the Atlantic's ocean floor.
"Girl Talk"
Although Heezen became Tharp's greatest ally in creating maps of the seafloor, he initially discarded her findings! Heezen, like the rest of the geological community at the time, didn't believe in continental drift. Tharp recalls the memory word-for-word:
When I showed what I found to Bruce, he groaned and said 'It cannot be. It looks too much like continental drift.' … Bruce initially dismissed my interpretation of the profiles as 'girl talk.'
Continental drift is the theory that all the Earth's continents were once connected. But the theory was very contentious; at the time of proposal, there was no known force on Earth that could rip apart continents.
This map -- the cumulation of Tharp's findings -- was published in 1957 and showcased the Mid-Atlantic Ridge which was previously obscured by water. Tharp shook the foundations of geology and scientists resisted the ideas her map proposed.
Tharp's "girl talk" was actually something full of factual scientific research and passionate enthusiasm.
In fact, not only did she prove continental drift, but she also gave rise to brand new theories concerning the Earth and new sciences.
What Tharp practiced in her ocean mapping was is now called bathymetry. Bathymetry is simply underwater topography. It involves mapping all the features on the seafloor as if all the water had been drained away. That's why we call it mapping the ocean!
Because of bathymetry, this map transforms from a blank canvas...
...to a map detailed with ridges, mountains, and, yes, volcanoes.
But Why Map?
Thanks to Marie Tharp, we now know that there is a whole world right below our feet. The seafloor is not flat but bumpy and mountainous. But is that all?
Why should we, today, map the seafloor?
Old sea maps with all their decorations served to navigate. The monsters and mermaids actually represent spaces of unknown seas.
Today, though less extravagant, our sea maps show how deep certain areas are, hazards in the water, or coastlines of land.
This is immensely important. For a cargo ship, preventing a crash by avoiding unseen water hazards is crucial to prevent loss of cargo.
Or for a passenger ship, to prevent loss of life.
Under the ships, bathymetry reveals where habitats like coral reefs are. This can lead to policies to protect these regions and by extension all of its inhabitants.
And over the ships, we must consider the weather. Oceans play a huge role in regulating heat from the sun and facilitating storm formation.
70% of the Earth are oceans. We've only explored 25%.
Understanding the seafloor helps us understand Earth.
So... why map the seafloor?
Because we are intrinsically linked to it in every way.
The Quest to Map an Ocean:
Mapping the seafloor today is quite a far cry from what it used to be.
Lead lining was the first method of mapping the ocean. Ships put out weighted lines behind them and the crew would periodically measure the line to see how deep the water was.
This method was incredibly time-consuming. After the disaster of the RMS Titantic, rapid developments in ocean mapping occurred to avoid another boat meeting a similar fate.
The developments lead to Sonar (SOund Navigation and Ranging). It functions by sending out echoes. When the echo bounces off the first object it reaches, it goes back to the ship, and the time taken is used to calculate how far the seafloor is from the ship.
We've went further to develop multibeam sonar; so instead of a ship strictly knowing what's directly below it, the ship sends out a wider signal to collect more data in a high resolution.
We've even developed collecting bathymetry data via satellites orbiting Earth; this is called satellite altimetry. Despite the enormous amounts of data, this data has very low resolution.
But even with all this data, it's still not in the format we want: a usable map!
Tharp had to process all her data by hand to get her map. Today, we can process data via computer software.
From Data to Map
"Raw data" is data collected as-is from the ship. It is exactly what the ship "saw."
"Cleaned data" is data that was processed to remove incorrect data. This is what's truly there and can be used in creating maps.
So, we clean this raw data by...
...removing all the wrong spots!
Let's take a closer look:
This is a closeup of seafloor data. Towards the middle of the image, there are many spikes that are errors in the data.
This is that same region after cleaning; all the spikes have disappeared. What remains is the smooth dip of the seafloor.
After all the data has been collected and cleaned, it can be published in official maps like Google Earth!
Let Them Map the Ocean!
Thanks to Marie Tharp, we have all these advancements in bathymetry from the collection of data to the dissemination of maps in an instant. Beyond that, we now have an overall acceptance in a seafloor that has mountains, valleys, and volcanoes.
Here are some of the features that bathymetry has revealed to us:
Mid-Atlantic Ridge
The focal point of Tharp's work, this was the first major discovery of modern bathymetry. This ridge splits the Atlantic in half and gave the basis for the theory of continental drift.
Mariana Trench
Found by sonar, this is the deepest point on Earth. It's actually the place where two plates of Earth meet.
Pacific Remote Islands Marine National Monument
Right off the Mariana Trench, multibeam sonar revealed a chain of islands in the Pacific. The picture above shows how important it is to have high quality data.
New England Seamounts
A seamount is any underwater feature, like a mountain. This chain of seamounts, however, are actually volcanoes stretching for nearly 750 miles.
Coral Reef on the Blake Plateau
The bathymetry above shows the largest (known) coral reef; it's just bigger than the state of Vermont. This area is still being investigated but it's suspected that a large ecosystem thrives here.
And all these features can continue to be revealed because of international efforts to map. Initiatives like Seabed 2030 are contributing to a complete map of the world's oceans.
Yet there are still massive gaps in the data.
Like here in the Indian Ocean. Monsoon season occurs in India every June to September. The nearby ocean directly affects the strength of monsoons.
Or here next to South America. This area of ocean is responsible for specific climate patterns that ultimately affect the world.
Or even in our backyard, in the Atlantic where the birthplace of hurricanes is.
Only 25% of the world's seafloor is mapped out.
And most of the effort has happened within the last decade.
In 2017, only 6% of the oceans were mapped. Russia, the largest country, covers about 3% of the Earth's surface.
Thanks to international efforts like Seabed 2030, by 2022, that number spiked to 24.9% which is equivalent to all the grasslands on Earth.
But that still leaves nearly 75% of the oceans unmapped...
...Or in terms of land, it's as if massive regions of the Earth have yet to be inhabited.
Continuing to support these efforts to map the ocean can only get us farther as an international community.
Marie Tharp began this work so now we must finish it.
In doing so, one day, we may truly understand this planet we call home.
Conclusions and Thanks
If you're new to bathymetry, like I was, I hope this piece inspired you to look into those global initiatives and informed you about the world within our world that's just under our feet.
And if you're part of the Girl Talk Program, thank you! For the Girl Talk Program team, thank you for teaching us about bathymetry and introducing us to an awesome community of women -- thank you to those as well! -- already in this field. For the participants, you all proved how our interconnectedness is key to all of our ultimate success.
Thank you to the Kaleta A. Doolin Foundation for providing the funding for this type of space that allowed this community to flourish.