Cindy Byers: Mud Volcanoes at Sea? May 6, 2018


NOAA Teacher at Sea

Cindy Byers

Aboard NOAA Ship Fairweather

April 29 – May 13, 2018

 

Mission: Southeast Alaska Hydrographic Survey

Geographic Area of Cruise: Southeast Alaska

Date: May 6, 2018

Weather from the Bridge

Latitude: 57 43.3 N
Longitude: 133 43.3
Sea Wave Height: 0
Wind Speed: 2 knots
Wind Direction: 202
Visibility: 8 Nautical Mines
Air Temperature: 14 C
Sky: High Cirrus Clouds   

 

Science and Technology Log

When I first learned that I would be on NOAA Ship Fairweather, one of the possible sites, I was told, was a survey including a mud volcano.  I did not know anything about mud volcanoes.  I knew about ice volcanoes on moons in our solar system,  but not about mud volcanoes. NOAA Ship Fairweather found evidence of the methane seeps coming from mud volcanoes, while surveying the Queen Charlotte fault last season.  A seep is where gases from below the surface comes out. The area surveyed the first week I was on the ship was just north of the seeps. I wanted to know more so I could share this information. Here is a little background.

CynthiaByersHeadShot

Cindy Byers from the ship’s deck in Southeast, Alaska

In 2015 geologists found a 700 foot gas plume and a couple other active mud cones along the Queen Charlotte – Fairweather fault. Although this fault is not in a highly populated area, it is very active. In the area where the geologists were surveying, liquid natural gas plants and a busy port were close by.  They already knew of earthquakes along the fault and that an earthquake in the area today could cause a landslide and generate tsunamis on shore.  Older mapping done in the area showed past landslides. But the 2015 survey was looking for the “seeps.”

Scientists first noticed the methane plume coming from the area near the fault.  The seep was from an underwater mud volcano. A mud volcano does not have to be made of igneous rock like a traditional volcano.  It is formed from gases and mud creating a volcano shaped cone.

Geologists have questioned whether these mud volcanoes may provide a lubricant that could actually lessen the friction on the fault in the area. It would cause the tectonic plates of area to slowly creep along.

NOAA Ship Fairweather also found these seeps during a mapping of the ocean floor along the fault.  Below on the right are the plumes of gas rising from the sea floor. Look how high they are rising.  Also notice the fan shape on the right. That shows the width of the multibeam sonar at this depth. The colored area on the left are also from NOAA Ship Fairweather’s multibeam sonar with the blues being deeper areas of the seafloor and green to yellow to red getting more shallow.  The circled areas show where the seeps were found while the fault line was being mapped.

Seeps

Soundings from the Multibeam Sonar over a mud volcano.

 

Seeps

Datum from NOAA Ship Fairweather showing a seep.

Life under the sea?

At these seeps, geologists have also found animals that live off of the nutrients of chemosynthetic bacteria.  This is bacteria that, instead using the energy of the sun (photosynthesis,) to make energy, they use the materials that come from thermal vents in the ocean floor.

Mud vulcano

Mud Volcano Photo credit NOAA

 

What are other geologic wonders of the area?

First of all there are hot springs! I learned about these hot springs from several of the people on NOAA Ship Fairweather.  They report it to be a fun place to visit for a little well deserved time off. There are many hot springs in other areas of Southeast Alaska too.  It is a draw for tourists to the area. The hot springs are produced because water seeps down a crack in the Earth’s surface and gets heated, then the super-heated water rises to the surface.

The geology of rock types of the area are also a wonder.  It is actually quite complicated, the landscape and seafloor features have been influenced by glaciation, volcanism and plate tectonics, and these geologic influences are still present today. The surveying on NOAA Ship Fairweather is vital to the understanding of the geology that shaped the area.  The clues that are beneath the sea help geologist begin to understand southeast Alaska’s dynamic past, and help to predict the geologic future.

 

Personal Log

After one week on the ship I feel like I just might have to stay!  The surveying is really interesting and the views are amazing. When I first arrived I was confused by the passageways and ladder wells on the ship, but now it seems so easy!  

Stateroom

This is my room on NOAA Ship Fairweather

Mess

This is the” Mess” (where we eat.)

I have discovered a few of my favorite places!  I love my small room with its own port hole. I really enjoy all of the meals and having time to talk to everyone onboard.  People come from all over the US and do a variety of jobs on the ship.

Linda

Member of NOAA Corps marking our location on a chart.

 

Tomorrow I will have a chance to go off the ship on the small boats. That sounds like great fun!

 

small boat

These are the small boats used for mapping in places that the ship can not do safely.

 

Did you know?

We just got to a new area with glaciers.  The one we could photograph today is Sumdum Glacier.  It sounds like a really funny name. It is a Native American word meaning, the sound glaciers make when they are calving, which is what it is called when ice falls off of them.

Sumdum Glacier

Sumdum Glacier

 

View from the ship

This is the view from the place the ship is anchored

Some information from:

“Active Mud Volcano Field Discovered off Southeast Alaska.” Eos, 30 Nov. 2015, eos.org/articles/active-mud-volcano-field-discovered-off-southeast-alaska.

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