Celebrating Geodiversity Day with five spectacular undersea features
Happy Geodiversity Day!
What’s geodiversity you ask? It’s short for geological diversity - the diversity of the natural parts of our planet that aren’t alive. The rocks, soils, sediments, landforms, and hydrological features, for example, and the processes that create and change these and other non-living features.
Geodiversity is literally the bedrock of our world, and of human history. As we strive to be more sustainable, we can’t just think about people, other animals, plants, fungi, bacteria, viruses and other life. We also need to take into account the wealth of services geodiversity gives us.
Geodiversity isn’t just the stuff we see on the land. It’s underwater too. Let’s take a peek at just five spectacular undersea features that make up some of our World’s geodiversity.
1. The West Mata Volcano
200 kilometres southwest of the Samoas, and ~1 kilometre below the sea surface, you’ll find the peak of the West Mata Volcano. It spans some 9 kilometres long, and 6 kilometres wide. If you wanted to go from the peak to the base, you’d have to head down another 3 kilometres.
Back in 2009, West Mata and the ROV Jason 2 gave us the first-ever recordings of an undersea volcano in action. Check it out here.
2. The Matanaka Caves
If you love caves you’ll love New Zealand’s Matanaka caves. At around 1.54 kilometres in length, Matanaka holds the title of the longest known sea cave in the world.
The cave was likely formed by freshwater making its way underground where it dissolved limestone away, leaving holes in the surrounding sandstone. As for the cave entrance, well that was probably the work of wave erosion.
3. Riko Riko Cave
Matanaka may be the longest cave in the world, but Riko Riko Cave claims the title as the most voluminous. Also located in New Zealand, Riko Riko is only ~152 meters long, but its egg shape cavern has a volume of a whopping 220,871,403 cubic litres!
4. The Challenger Deep
Want to go to the deepest known place on Earth? The Challenger Deep is for you! Resting some 11 kilometres below the sea surface there aren’t many people who’ve made it down. In 2022, Dr Dawn Wright, Chief Scientist at ESRI, geographer, oceanographer, and all-around amazing person became the 23rd person to have ever visited the Challenger Deep, the fourth woman, and the first person of African descent.
Take a peek at this video of Dr Wright’s adventures into the deep.
5. Cascadia Margin “Champagne” Seeps
Stretching from Northern California up to British Columbia, the Cascadia Margin is home to one of the largest known methane seeps on Earth. The methane is produced by microbes which, when conditions are right, bubbles up from the seafloor. Some say the effect looks like champagne bubbles. Some say it looks like little farts. Either way, it’s pretty neat.