Monitoring the Earth from Space with SeaWiFS
1: Why should we care about the oceans?
2: Why study the oceans from space?
3: What color is the Ocean; and why do you need a satellite to tell you?
4: Phytoplankton - All things great and small
Imagine that you are standing on a beach looking out over the
vast expanse of seemingly featureless ocean that lies before you.
If you turn around and look at the land on which you are standing,
it seems filled with life. Birds hover overhead, trees dot the
landscape as far as you can see and perhaps you might be lucky enough
to see a few other animals scurry past. Indeed, the surface of this
planet we call Earth seems filled with life. However, looks can
be deceptive.
If you think of where the creatures you can see
live, you'll realize that they inhabit a very thin veneer of the
surface. Various worms, bugs and other creatures that are better
left alone may dig a few feet below the surface into the rich topsoil.
Birds while gliding happily through the sky, must find a place to
perch, to build a nest and to find food. Even the most adventurous
bird can only perch as high as the tallest tree. So life on land
really only exists in a band perhaps several hundred feet thick....
regardless of the actual elevation of the land surface itself.
So when you consider the fact that life in the oceans can be found from
the surface all the way down to the very bottom of the deepest submarine
trench, it is not surprising to realize that the oceans represent
over 99% of the living space on Earth....we are indeed living on what
is truly an Ocean Planet.
More Information:
The oceans are different.....very different. Back in 1960
when people descended to the deepest part of the ocean for the very first (and last)
time, they turned on the outside lights and there, in front of
the viewport at a depth of over seven miles (35,802 ft (10,912 m)),
was a strange looking little fish looking back at them and probably
wondering who these visitors were. This
"flatfish at the very nadir of the earth" was living at a place where
the water pressure was more than 8 tons per square inch, or the equivalent
of one person trying to support 50 jumbo jets. Just to give you a
sense of scale, at that depth you could cut Mount Everest off at sea
level and put in on the ocean floor at the bottom of the Marianas Trench,
where that little fish was swimming, and there would still be over a
mile of water over the top of it.
While we make think that the only mysteries left to discover await us on
distant planets, there are still plenty of wondrous creatures to study
and incredible places waiting to be explored right here in our own
backyard....especially in the ocean.
Did you know that the blue whale, Balaenoptera musculus,
is the largest known animal ever to have lived on sea or land and
can reach more than 110 feet and weigh nearly 200 tons - more than the
weight of 50 adult elephants? And to show that there is still plenty
left to see, one recent study of a deep-sea community revealed 898 species
from more than 100 families and a dozen phyla in an area about half the
size of a tennis court. More than half of these were new to science.
And finally, consider the fact that there exists a creature in the oceans that we
know to be the world's largest invertebrate, that can grow to at least 60
feet in length, has eyes as large as vollyballs but which has never been seen alive in its' natural habitat. Although the Giant Squid may be the stuff of legend,
it is very real indeed and is just one of the as yet unsolved mysteries
of the ocean.
The aspect of the life in the ocean that I would like to focus on in
this discussion, however, is at the other end of the size spectrum
from the giant squid. In fact, they are actually microscopic and
are called Phytoplankton - those tiny little plants
that drift with the currents throughout the ocean but play an
absolutely critical role for all life on this planet.
You may ask "why should i care about a bunch of tiny little floating
plants in the ocean that i can't even see, and what could they possibly
do for me?". Well, it is safe to say that without phytoplankton,
life on earth as we know it would never have happened and without them,
it would cease to existi.
Just to give you a few facts to whet your appetite:
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gene carl feldman (gene@seawifs.gsfc.nasa.gov) (301) 286-9428