We have a more accurate map of the surface of Mars than we do for Earth’s ocean floor. Right now, researchers have a blurry, indirect picture of the seabed from satellite imaging, some sonar data and samples collected from ships.

Yes, but: There's an avalanche of data about the chemical, physical and biological properties of the ocean, and scientists are beginning to use machine learning to tie that data to limited scientific records in hopes of piecing together a better picture.

Why it matters: The ocean is the planet's largest carbon sink thanks to processes that critically depend on the seafloor, and sediment layers hold a record of the ocean's chemical and climatic history. Understanding the ocean floor is key for climate forecasts and predicting geohazards like tsunamis as well as for efforts to mine the seas for methane and minerals.

"The seafloor is one of the more remote places on the planet. It is hard to get a lot of data," says Warren Wood, a geophysicist at the U.S. Naval Research Laboratory in John C. Stennis Space Center in Mississippi. Instead, researchers want to find proxies for what's happening in the deep ocean. "If you can have some idea of what is out there without going out and measuring it, it is a phenomenal achievement."

Dive deeper: Read full story here.

A Kemp's ridley sea turtle being rescued in Cape Cod, Mass. Video: Saving Sea Turtles Movie

From Axios' Erin Ross: Hundreds of young, hypothermic, near-death turtles wash up on the shores of Cape Cod every year. But when Bob Prescott first found a Kemp’s ridley sea turtle on a frigid Massachusetts beach in 1974, he thought it was an anomaly.

But, the number of stranded turtles has steadily climbed — over 1,200 washed ashore in 2014 — and experts think climate change is partly to blame.

More: Axios traveled to the National Aquarium in Baltimore, where about 30 of those turtles were being treated and monitored. Read the rest of Erin's story and watch the video.

• Feast or famine: Cameras mounted on polar bears have captured the tough life of these hunters — and climate change could make it tougher, Erin writes.
• Robotics: A new survey identified the field's grand challenges, including materials for soft robots, power sources, the ability to adapt and learn, how they'll interface with humans, and ethics, per Erica Pandey.
• Take note: Most women don't know their risk for heart disease, according to a new poll.
• ICYMI: Erica on China's space strategy and bioethicist Jonathan Moreno at the University of Pennsylvania on the country's blockbuster biotechnology week.

Scientists know that wastewater injection related to fracking for oil and gas can induce earthquakes. A new study published in Science Thursday found that the deeper these injections go towards a layer of rock called the crystalline basement, the more likely they are to cause earthquakes.

Why it matters: Oklahoma never used to experience many earthquakes, but since 2009, a number of damaging temblors have shaken the area. "State regulators could cut about in half the number of man-made quakes by restricting deep injections in the ground," study author Thea Hinck told the Associated Press.

Dig deeper: Read Axios' Eileen Drage O'Reilly's full story here.

• Faster than you think: New insights about the speed of evolution are reshaping the field of ecology, Rachael Lallensack reports for Nature.
• A good debate: Eric Lander of the Broad Institute writes in the Boston Globe that what U.S. leaders should be arguing about is the country's leadership in science and technology. Among the issues he flags: China's investment in R&D, U.S. leadership in AI and energy, and attracting international students to universities.
• Red or white? The genetics of "supertasting" may explain why we may not detect a particular note or like a wine-food pairing. "You may just have a different genetic profile from whoever recommended it," explains Brooke Borel in Wine Enthusiast.

In the depths and darkness of the ocean, snow-like particles gently waft toward the seafloor. The sticky mix of dead diatoms and other plankton, their feces and bits and pieces of a life once lived at the surface can sink up to 1,000 meters in a day, carrying carbon dioxide captured through photosynthesis at the top to the deep ocean. There, it can sit for 1,000 years before the water turns over.

Why it matters: "It is a big chunk of carbon dioxide that these organisms are sequestering in the deep ocean through this process," says Tim DeVries from UC Santa Barbara. Without it, there would be roughly 25% more carbon dioxide in the atmosphere than at present.

The unknown: What happens to marine snow between the surface and the seafloor — i.e., how much of the carbon dioxide photosynthesized on the surface makes it to the deep ocean and how fast — is largely unknown. Understanding the processes is critical for predicting how the ocean will respond to climate change.

"Right now, models assume the ocean will continue taking up carbon dioxide at the same rate," says Uta Passow, an oceanographer also from UC Santa Barbara. "But we have no idea."

• In a recent study, researchers used particle imaging and a technology similar to sonar to assess how currents and zooplankton. They found an increase in carbon sinking at intermediate ocean depths due to zookplankton eating and defecating as they swim toward the surface at night and return to the deep before dawn.

"In the text book view of things, the ocean is big and slow, and things happen gradually. But actually what we see in these pictures is that it is dynamic, changing over time, and involves processes that we don't understand well," says Eric Galbraith from the Institució Catalana de Recerca i Estudis Avançats in Barcelona.

• Marine snow can also attach to oil and drag it to down to microbes that otherwise wouldn't have seen it and which then incorporate it into the food chain. "Marine snow is very important transport vehicle for oil and oil particles in oil spill situations," says Kai Ziervogel from the University of New Hampshire, who studies this process with Passow.

Measuring marine snow is challenging. Much of what scientists know comes from laboratory simulations and samples trapped in large funnels placed at different depths. This summer, a NASA field study will simultaneously take biological and chemical measurements from boats and collect satellite data in an effort to improve researchers' data.

A snowy perspective from Rachel Carson in her book "The Sea Around Us":

"I see always the steady, unremitting, downward drift of materials from above, flake upon flake, layer upon layer — a drift that has continued for hundreds of millions of years, that will go on as long as there are seas and continents."