- After 20 days at sea,
here are a few of our results from expedition
NA133, Lu'uaeaahikiikalipolipo.
This Hawaiian language name represents the journey to,
and the work in the Kalipolipo
or the deep blue ocean.
This expedition used the multi-beam and sub-bottom profiler
to map the Lili'uokalani seamount chain.
Inside the Papahānaumokuākea Marine National Monument,
which is Northwest of Hawaii.
Papahānaumokuākea encompasses over
580,000 square miles of the Pacific Ocean,
making it one of the largest marine conservation areas
in the whole world and an area larger than all of the
United States national parks combined.
Let's join Nautilus mapping coordinator,
Erin Heffron,
to walk us through a deep dive
of what the mapping data has revealed so far.
- [Erin] Okay.
Doing a data walk through of our mapping effort on NA133.
So about 12 days ago, we left Oahu.
That's what we have here.
And it started mapping when we got outside of Kauai.
Cause if you look in this area, at our base map,
this area has all been pretty well mapped.
So when we see this really detailed topography
in our base maps,
then we know that mapping has already been done.
So we waited until we were further outside of Oahu
and through the Kauai channel to turn on our sonars
and start mapping.
So where you see this bright data,
that's where we started with our sonars on.
And you can see as we move along,
we're starting to approach gaps in the data.
So just taking a look,
when you see this really nice,
kind of high resolution, bumpy,
really, really detailed topography,
that's where mapping has been done.
Whereas when you see this kind of very smooth topography,
that is just an estimate of what the sea floor is typically
coming from satellite altimetry, but not,
not truly mapped data.
So those are the gaps that,
we try to hit as we are making our way out.
So we started mapping,
I believe on the 24th and just heading out and some just
really nice, rich features and things
that we hit on the way.
And as we got a little further along,
we started to see some really,
really cool features that didn't necessarily show up.
So here's one example of a ridge
that we got to cross on our transit.
If I turn off our data,
this is the satellite altimetry estimate,
and so from the satellite altimetry estimate,
we have, something was there that did show up,
in the altimetry data, but it didn't get much detail on it.
We then look at our data in that location,
turn off the background.
See we got some really nice detail over that marine ridge.
These features were quite cool and there wasn't too much
indication of them in the base map.
So if I, again, turn off our data,
could barely see just like a gentle indication.
That maybe something's there, just a slight bump.
And if we turn our data back on,
there is these cool little half ring features
with what looks like maybe a little volcanic mound
or something in the middle.
And these are quite cool,
and didn't really show up in the altimetry data at all.
Continuing along our transit towards King George,
we crossed over some mapped ridges,
it's quite beautiful, detailed data.
And then this was a seamount, that we crossed,
that was unmapped.
So again, I'll turn off our data
so you can see the difference.
In the background you see
some features that were really nicely mapped,
and I believe that might be Nautilus data
from a few years ago
that mapped those seamounts in the back,
but this seamount was unmapped, again,
there's an indication that it's there
in the satellite altimetry
just not a lot of detail,
but we specifically went over this one
by request from our lead scientist
and got some nice detail
in passing over the ridge.
And just to be clear too,
all of this data is exaggerated three times,
which you can see on my screen here.
So it makes it look a little more dramatic than it is,
but helps us to really see
all the nice detail we got with our multi-beam map
Continuing on.
And then finally, three or so days after we left Oahu,
we made it to our first major seamount.
And so this is the King George seamounts,
and you see both the base data and our data.
So I'll separate those out now.
I'll start by showing the pre-mapping.
So this is what it looked like before, again,
just from satellite altimetry base data
and the grid that we're using to show this
is the GMRT or Global Multi Resolution Topography model.
And that's a model that's continuously updated
as new data comes in.
So, where there is multi beam data they add it in.
And that's the example in the background here,
the swathe of data, was from the GMRT grid as well.
And then they fill in the areas
that are unmapped with other resources that are available.
So that would be the satellite altimetry
or occasionally maybe single beam data,
things like that.
So that was King George prior to our mapping efforts.
And then king George after,
turn off the background data,
we can see that it was indeed a flat topped guyot,
also get all this really,
really beautiful detail up and down the ridges
I actually find the bases of these seamounts
to just be so cool with all of the detail
of this, I don't know, really detailed ridge
and typography and all the bumps and things at the base.
I just think are the coolest,
because you just don't get that detail
in the estimates.
All right, and moving on from King George,
we then completed mapping on King George and did about
15 to 16 hours of transit.
Got some nice, rich topography
and then arrived at Loudoun seamount.
So we started this quite a few days ago,
had to leave Loudoun for a while
and flee south because of weather.
So you can see our transit,
we then turned off our sonar
as we went through part of the sanctuary.
We hung out south of the sanctuary for awhile,
and then we returned to finish Loudoun.
So, now I'll turn on the multi-beam data
and you can see the areas
where there's a difference between the
satellite altimetry and the data we collected.
And if I turn off the background map.
So Loudoun was a pair of seamounts,
really, really close together with this kind of
connecting saddle between them.
Really beautiful detail on top of the guyot.
This was also a flat top seamount,
but we see these nice kind of cones and stuff
forming at the top.
Quite interesting.
We also thought this was pretty interesting,
this little, kind of divot and flat landing space
up near the summit.
And so I guess what's important about mapping is that
prior to us doing this mapping yes,
there's an indication of what's there,
but never the amount of detail
that you can get with a multi-beam.
And it becomes important
when we want to explore these seamounts
with our ROVs we need to have a kind of better idea of
what we're going to be putting the ROVs down on
with more detail than what's available
through the satellite altimetry estimates.
So we're doing the seamount mapping
specifically to support our ROV expeditions next year,
so that we have really, really good base maps
for the navigators and ROV pilots
to really know what kind of slopes
and topography to expect once we take the vehicles
down there for exploration,
and just in general,
I think mapping is important because it's the,
the base map for everything.
So as we try to understand the world oceans and improve
climate models and everything,
the bathymetry really is the base.
It's the first layer,
and it's just so interesting that that first layer
is 80% guesswork at this point,
we've only really mapped about 20% of the world oceans.
And so the rest of it is just an estimate,
and it's a pretty good estimate,
but it's not necessarily fact.
And you wouldn't have the detail of a level like this,
where, what looked like possibly
just one really large seamount,
going back to the base data.
There's some indication that maybe they're separate,
but not as much as what we can see
once we have it really, truly, thoroughly
mapped with the multi-beam.
So we completed Loudoun
and we transited directly to Mercury,
which is so close that we didn't even,
couldn't even start a new survey project.
It was just so close,
to start going up the side of Mercury.
So we started with an exploratory line
to cross the entire top.
So that was this kind of line marching up this ridge.
And we crossed over the top,
came back down the other side
to really get a feel for the extents.
And now we're mapping our way
from north to south on Mercury seamount,
and this state has not completely processed yet.
So there we see an artifact of the multibeam,
there's an error there
that's causing that spike.
So as part of our work as surveyors and mappers,
we will go and get rid of those.
They're just anomalies.
Sometimes the sonar picks up fish,
or things in the water column,
or just loses the bottom,
especially over really steep topography
like we have here.
And so you'll get these spikes.
And that's when we talk about cleaning multibeam data,
that's specifically addressing issues like this.
So before this data is finalized, that spike will disappear.
- During expedition NA133, Lu'uaeaahikiikalipolipo
We mapped over 32,980 square kilometers across the
United States exclusive economic zone.
This data contributes not only to a global effort
to map the world's oceans
with our partners Seabed 2030,
but also contains the maps needed for future ROV dives,
and exploration of the incredible region
of Papahānaumokuākea Marine National Monument.
More exploration soon.
Thanks all!