It's been months since Malaysia Flight 370 disappeared en route to Beijing from Kuala Lumpur. The plane likely went down in the Indian Ocean off the coast of Australia, but not a trace of it, or any of its 239 passengers, has been found.
As the search continues in the open water, it's become clear how little we know about the landscape of the deep ocean floor. The Wall Street Journal's Daniel Stacey has been writing about the challenges of finding the wreckage and he joins Take Two to talk more about it.
On why there's not more information about the search area:
"Most of the floor of the ocean has only really been estimated using a kind of satellite science called satellite altimetry. People fire radar from satellites and it bounces back and gives them a picture of the surface of the sea.The surface of the sea fluctuates over mountains and valleys, it has a viscosity to it, it sort of isn't just uniformly flat. From that, you can determine some basic features at the bottom of the sea, but only within the accuracy you say of, you know, the height of the Eiffel Tower. So, we don't know that much about it."
On the technology that could be used in the search
"They need to get under the water with sonar and get within, let's say, 100 feet of the bottom of the sea. They either tow sonar devices on long, long cables that could be 10 kilometers long or they send down what they call autonomous vehicles -- they're basically undersea drones which swim around themselves and they bounce sonar off the bottom of the sea and look for debris."
On the most impressive wreck recovered in the deep sea:
"There was a really deep shipwreck located in 1996. It was what's called a blockade runner, a German ship that was loaded up with tin, copper and cobalt and was trying to get back to Germany during the latter stages of the second World War. It sunk in the middle of the Atlantic Ocean at almost 19,000 feet. It's the world record for the discovery of a shipwreck. That's just an astonishing depth to find something at, we're talking almost six kilometers, I think, under the sea."
On the difference between finding planes and finding ships underwater:
"The hull of most ships, when they sink, might snap in half or get a big hole and just sort of sinks to the bottom in one piece. A plane hits the water at very fast speed, even if it's gliding, and usually it fragments. There are a few bits of the plane which I guess typically from experience, remain intact. The engines are very robust, the front of the plane is really strengthened to deal with headwinds. The tail usually takes the impact last and retains its form. When this sinks to the bottom of the sea, it can just look like rocks, and you have to be really careful not to miss it. When you do a search like this, you only go over a lot of the areas once. If you didn't see it, you may be searching months and months, and you've passed it by."