The Sulfur Seeps of Maug

We woke today to squalls covering Maug, a group of three islands that form the rim of a submerged caldera of an ancient volcano.  There are no known eruptions since the discovery of Maug in 1522 but the NOAA Vents program has been exploring the Mariana Trench area for submerged volcanic activity.  The caldera is about 1.5 miles wide and averages 600 feet deep with a twin-peaked lava dome that rises in the center to within 60 feet of the surface.  Our dive sites are located both inside and outside of the caldera with one hopefully planned for the lava dome area.  

The most spectacular site of the day was on the inside edge of the north island.  We dropped into an area that had 100% coral cover for as far as the eye could see.  The coral, Plate and Pillar Coral (Porites rus), extended from the top of the reef slope at 20 feet to at least 100 feet deep (after which we couldn't see the bottom).  As we followed the slope around a bend, we came to an area that looked like a land slide of orange mud and was completely devoid of coral.  As we got closer, we noticed that there were little bubbles coming up from the mud and when I put my hand down, it was hot to the touch.  We had found sulfur seeps!  We took time trying to snap pictures of the bubbling mud and one of our scientists even went barefoot, just to wiggle her toes in the sand.  Too soon it was time to go back to the surface for more rain squalls and a trip back to the ship.  We will be at Maug for the next two days and I'm looking forward to what else it has in store.

I hope your night is going well.  Here are a few pictures to keep you going ...

Take care,

Cristi

Plate and Pillar Coral


Purple Queen Fish and a Cleaner Wrasse


Entering mud slide area

The bubbles are sulfur coming from submerged volcanic activity


One of our scientists refusing to come up from the dive and into yet another rain storm