Ask an Explorer

Questions answered during the expedition are below.

Question from:  Lisa, Palo Alto, CA

How do the exploration techniques overlap with those that are used to find active volcanism and vents?

Answer from:  Susan Merle, Sr. Research Assistant, Oregon State University, Newport OR

The exploration techniques that we use for the discovery of active volcanism and vents are very similar to those being used to find the sulfide deposits, and include mapping, CTD (conductivity, temperature, depth) sensors, and then exploration of the seafloor with a Remotely Operated Vehicle (ROV).

Question from:  Rita, Escondido, CA

While I was watching, the explorer was commenting that the water was murky and that the camera couldn't see very far.  What is making the water murky at these depths?

Answer from:  Susan Merle, Sr. Research Assistant, Oregon State University, Newport OR

There are various reasons the water is murky at depth. Something called "marine snow" accounts for most of this murkiness.  “Marine snow” is comprised of all the items in the water column, biological (small marine organisms) and sometimes geological (sediment, etc.) that fall through the water column to the ocean bottom.  Much of the ocean bottom is covered in deep sediments (from rivers on land, blowing sand from deserts, etc.) that have accumulated over millions of years. Those sediments can get stirred up by the thrusters on the Remotely Operated Vehicle (ROV) and also cause the water to get murky. There are also biological mats on the seafloor near hydrothermal vents that can get stirred up by the ROV, decreasing water clarity.

Question from:  Dawn, Redlands, CA

What geographic information system maps and analyses are being prepared and may we see some of them?

Answer from:  Susan Merle, Sr. Research Assistant, Oregon State University, Newport OR

We use ArcGIS on a daily basis out here. I pulled together all our data in this area and have created the NE Lau database. GIS is also used for dive planning, data analysis, etc. We have a GIS map indicating the dive plan before every dive.  And we have also been using GIS to analyze the navigation we receive from the Marum ROV group, amongst other things. We use GIS because it is such an amazing tool for overlaying all the vast datasets we have collected in this area (and all the places we work).  To name a few of those datasets, of course our base layer is always bathymetry (from satellite altimetry, ship hull-mounted multibeam sonar, to AUV and ROV micro bathymetry). Those data sets range from 1850m resolution to less than a meter, respectively. Then there is all the various vehicle navigation (ROVs, AUVs, camera tow tracks, dredge tracks, etc.) plus samples from all those vehicles. We also used Fledermaus for 3D depictions of the seafloor and flythrough movies (see the NE Lau Basin Virtual Fly-through page on the website). All the 2D maps on the website were made in ArcGIS. We also use GIS for multibeam survey planning. We literally have ArcGIS open on our computers at all times.  We'll try to post more maps with the website.

Question from:  Dawn, Redlands, CA

What is the possibility of seeing sulfuric ponds or even red hot lava at the bottom of the pits they are exploring?

Answer from:  Susan Merle, Sr. Research Assistant, Oregon State University, Newport OR

We did dive on Volcano O yesterday and were not able to get the ROV down into the crater pit at the cone in the caldera. There was too much of a plume for the pilots, but there is a good possibility that there could be a sulfuric pond at the bottom of that pit. It is an awfully harsh environment and it's understandable that they did not want to risk the integrity of the vehicle. The plume pouring out of the pit is high in sulfur content and there were lots of sulfur sediments on the cone.  We are all excited for our dive to West Mata, and we are hoping to see red hot lava at the summit, like we did when we came out here in 2009.

Question from:  Mike

What is the process for figuring out if a discovered organism is, in fact, a previously unknown organism?

Answer from:  Tim Shank, Associate Scientist, Woods Hole Oceanographic Institution

Once the organism is collected and brought into the lab, we examine its morphology. That is, we look at the features and the shapes of the features the organism has and we compare those features to what is known in the published scientific literature. Each species has to be described and named formally in an accepted scientific publication.  For each species, there are diagnostic characters that define that species.  For example, the number of teeth on a shrimp's nose, the branching pattern of a coral, and the orientation of suckers on an octopus' arm are used to define those species. With a pile of drawings and descriptions from species publications in front us to compare to (and most often with a microscope), we examine a collected specimen. After often tedious examination, if it does not show diagnostic characters for any known species, then we propose it as a previously unknown species, describe its features and designate it as new species. To date, there are more than 650 species described from hydrothermal vents. That is almost equal to one species being formally described every 10 days since hydrothermal vents were discovered.  Note too, that it often takes months to examine and formally describe a new species.

Question from:  Oceanography Class, United States Naval Academy, Annapolis, MD

It looks like in some of the past released videos, there have been instances when the ROV gets really close to underwater volcanoes.  How close has the Quest 4000 really been, and has it sustained any damage by getting close to these massive underwater features?

Answer from:  Susan Merle, Sr. Research Assistant, Oregon State University, Newport OR

On this expedition we have experienced some high winds and seas, too high for the ROV to dive, so we have been filling that time with other operations like CTD and seafloor mapping work. On the four dives that we have completed (Vai Lili, Fonualei South, Volcano O and Mata Ua), two of those sites have required extraordinary ROV maneuvering and care. The cone at Volcano O is covered in sulfur sediments with a pit at the top where a thick sulfur-rich plume is wafting up from the bottom. We tried to get the ROV to venture into that pit to investigate the source of that plume, which we believe could have been one or many molten sulfur ponds or vents. Sulfur is corrosive and can damage the vehicle, so after descending about 10 meters down into that pit and losing visibility, the ROV pilot decided it was too dangerous to descend further.  On our dive to Fonualei we discovered huge, slender, sulfide chimneys up to 30 meters tall (~100 feet).  Sampling the hot fluids from the top of those chimneys is no easy feat. The ROV has to hover next to the chimney, and manage the tether connected to the ship - taking care to keep it from tangling around the chimneys or getting burned by the hot fluids. The ROV pilots did a great job there and we successfully sampled fluids and sulfides at that site.  We have not yet visited West Mata volcano where we witnessed the eruption in 2009. We are not convinced that it is still erupting, so please stay tuned.

Question from: Oceanography Class, United States Naval Academy, Annapolis, MD

You are about half-way through this expedition. What is the most exciting thing to come out of what you have gathered so far?

Answer from:  Susan Merle, Sr. Research Assistant, Oregon State University, Newport OR

For me it is the realization of what a volcanically active area the Northeast Lau Basin is. We have done CTD casts on very small features (the last was only 400 meters above the seafloor) and discovered there was a hydrothermal system on that small seamount. In the past the belief was that an edifice had to be large to have a magma chamber beneath it -- the source of the heat for these hydrothermal systems. We are discovering that this whole area seems to be much more hydrothermally active than we had ever imagined. When the weather improves we hope to get the ROV down to the seafloor and get a glimpse of more of these systems.

Question from:  Oceanography Class, United States Naval Academy, Annapolis, MD

How difficult is it to retrieve microbial samples at depths of greater than 1000m, and would a change in pressure and temperature from the sampled site environment to on-board ship conditions potentially result in a loss of DNA material or microbial diversity?

Answer from:  Rick Davis, Graduate Student, Oregon Health & Science University, Portland OR

Bacterial cells from the deep-sea are generally free of gasses that would expand with a loss of pressure and rupture their cells. Studies have shown that pressure has a minimal effect on bacterial cells until the depths are greater than 4000 meters, and bacteria have even been cultured from the bottom of the Mariana Trench without any added pressure to the cultures.

Thermophilic bacteria often go into a "survival mode" when they are removed from their warm environment. These microbes go into a state of reduced metabolism- similar to hibernation- to survive for long periods of time away from their preferred habitat. We often grow thermophiles in the lab that can survive for years without any nutrients when they are placed in a refrigerator. This is why we quickly cool our samples after we retrieve them from the ROV, and we quickly freeze the microbes at -80 degrees Celsius until we are back in our lab and can extract DNA from the frozen cells.

Question from: Story, Modena, Italy

Are the scientists testing the use of newly invented devices for collecting data on this voyage?

Answer from:  Susan Merle, Sr. Research Assistant, Oregon State University, Newport OR

Scientists are constantly innovating collection devices before an expedition, and while on board the research vessel. On this expedition there are microbiologists from OHSU who have devised a new sampler that preserves the DNA of the microbes they collect on their ascent through the water column (see Rick Davis's answer to a previous question). We also have a scientist on board, John Lupton, who has devised a huge funnel-type sampler to collect the magmatic gas bubbles that rise from erupting volcanoes. It has a long extender arm so that the ROV doesn't have to get too close to an erupting vent. Scientists also have to work “off the cuff” and improvise their sampling devices at sea depending on the capabilities of a particular ROV and how safe they feel when attempting to sample. The best laid plans of mice and men often change. Luckily we have a smart bunch of individuals on board (both the science party and ship's crew) who are equipped to deal with any improvisations that are necessary.

Question from:  Story, Modena, Italy

When you are exploring near the subduction zones, have you been able to witness any earthquakes?

Answer from: Susan Merle, Sr. Research Assistant, Oregon State University, Newport OR

We have not witnessed an earthquake while on the ocean floor with the ROV, but have certainly witnessed the results of earthquakes after the fact, like huge fault scarps where mass wasting events have occurred, etc.

Question from:  Story, Modena, Italy

Have you found new species of organisms on this voyage?

Answer from:  Susan Merle, Sr. Research Assistant, Oregon State University, Newport OR

Tim Shank, in an earlier answer, explained the process to determining whether or not an organism is a new species. Yesterday at West Mata we witnessed an amazing congregation of shrimp near the summit. Tim believes there are possibly 4 species of shrimp on the volcano now. There were only 2 species when we were here in 2009. He was not able to sample those shrimp due to problems with the suction sampler, so we will only be able to observe them with the high definition video. That is unfortunate, because one really needs a specimen to determine whether or not the species is indeed a yet-unidentified one. They also collected a crab on the expedition that they do not believe has been identified, and possibly more species. We won't be certain until we're back on shore. And, we're not finished yet so there could be more surprises to come.


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