Hawaii Teacher on Board
By Naidah Gamurot
Oct. 19, 1998. Today was rather uneventful. The forward
camera on ARGO went out overnight, so it's been onboard all day. In the afternoon we took
a wax core sample from the ocean floor. There were very few particles of rock or sediment
on the cores.
We did do a little more traveling than we had the past couple of days. This morning we
were far out to sea, with no land in sight. Tonight we're in close enough to see the Big
Throughout history, lots of people have traveled the seas and were able to tell when
they were getting close to land. How do you think they did that?
Well, one way was if there were birds nearby. They knew the birds must have a home on
land within flying range. Another way is to look for clouds that can form above islands.
If the island is high enough, it will force air masses upward. As the mass climbs, it
cools, and clouds form. So, even if you can't see the island from the sea, you might be
able to see the clouds accumulating over it. The Big Island presents a unique twist to
that method. Mauna Kea and Mauna Loa extend far above the usual 3,000 foot cloud base
common for Hawaii. (Both volcanoes have elevations higher than 13,600 feet.). On some
days, you would actually see the tops of the volcanoes before you would see an
accumulation of clouds.
Here's one that works well for us on the ship. The prevailing winds in Hawaii are the
northeast trades. The Puna Ridge runs to the northeast. This means that the trades blow
from the outermost portion of the Puna Ridge towards land. And, since swells move in with
the prevailing winds, by following the swells, we can determine in which direction the
island can be found. Today we were steaming into the swells. Were we moving toward the Big
Island or away?