This has to be seen to be believed: An Australian couple vacationing in Papua New Guinea heard that a local volcano, Mount Tavurvur, had been erupting. They got on a boat to take a closer look and got the ride of their lives (make sure you’ve set the video to HD, the detail is amazing):

Update, Sept. 8, 2014: Well, drat. It looks like the video was taken down. There are lots of copies on YouTube, but they were posted, as far as I can tell, without the owner’s permission, so I won’t link to them. I’ll see if I can find a legit source and embed it here again. My apologies.

Holy yikes! The video was taken by Phil McNamara, and posted on the Facebook page of his wife, Linda. The volcano has been pretty active historically and has caused a lot of damage; it’s killed many people, and buried the nearby town of Rabaul in ash in 1994. Rabaul used to be the provincial capital of the island of New Britain, but after that eruption the capital was moved to another location.

This eruption was smaller in comparison, but holy cow. It was still amazing. In the video you can see lava blasting upward hundreds of meters, falling apparently slowly due to distance. Given the timing delay of the shock wave—13 seconds or so—the folks on the boat were just over 4 kilometers (2.5 miles) away.

You can see the shock wave traveling down the volcano slope at 00:13 and then ramming the air above the volcano a few seconds later. The sudden compression condensed the water vapor in the air, so you can see ephemeral clouds forming in a rough circle above the explosion. I looked carefully but saw no sign of it traveling across the water.

The volcano has been spreading ash across the island, as you can see in this photo taken by Landsat 8:

On NASA’s Earth Observatory page they have a before-and-after shot, and you can see that what’s now brown and ash-laden was green just a few months before.

Looking at all that and reading about this volcano, I’d say the McNamaras were pretty dang lucky. This explosion could’ve been a lot worse, and as it is they got some fantastic footage and a great story to tell

Tip o’ the caldera to about a hundred people who sent me this, but the first was Nathanial BB.