...but in the game, they look like this. I saw this rift as I was being pursued by another player behind me, who had already gotten one good shot in, so I booked it toward the rift.
The rifts seem to be scattered randomly across the map, and only stay in one place for a short amount of time before disappearing again, but I had great luck finding a few just to the southeast of Loot Lake.
They're pretty easy to spot, just because they shine so brightly from a distance.
As you can see in the screengrab above, they shine even brighter than the treasure chests.
In fact, as I got closer, I noticed a second one close by.
It's not yet clear how many rifts are on the island at a time, but I found a handful without having to look too hard, so they must not be very rare yet.
But you can only use a rift once. They simply disappear after the first player enters.
As I got closer, the rift began to open up and a mesmerizing, multi-colored ring formed around it. The other player was still hot on my trail, so I jumped in, hoping for a quick escape.
To enter the rift, you don't have to press any buttons, simply walk into it.
They also emit an unmistakable, spacey sound effect that gets louder as you get closer.
The next thing I knew, I was upside down, way up in the sky. Before I had a moment to realize what had happened, I materialized through another rift way in the sky above the island, directly above the spot where I had entered.
I then proceeded to parachute back onto the island, in the same location where I had entered the rift. Luckily, my attacker had moved on, and wasn't waiting for me at the bottom.
I had successfully escaped my attacker, but was so taken aback by the teleportation animation that I didn't manage to get the next screenshot, so I ran to the second rift to try again, after making a pit stop at the treasure chest.
The second time, I was quick enough to capture my exit from the rift, as it spat me back onto the island in a flash of light. (You won't have to worry about screenshotting your escape, I just wanted to be able to illustrate what it looks like.)
For the sake of research, I tried teleporting through the rifts a few more times, and was always spit back out in the same area I had entered.
This means the rifts are unfortunately not yet a great solution for long-distance travel, and offer essentially the same effect as getting to jump from the Battle Bus a second time, but with a pre-set destination.
But still, the rifts offered a quick getaway in my time of need, and a really fun trick that I wanted to do over and over again.