The Hawaiian Islands are, of course, made out of lava since they are of
volcanic origin. But lava changes with age. Weather and biological processes
break it down. On the older islands the surface is soil, lacking in some
nutrients, but able to support luxuriant vegetation.
On the Big Island, however, we have much younger lava. We got to see some
that was a couple of centuries old, and some that was a couple of hours old.
 |
 |
Up near our condo was lava that was from the 1880 eruption of Mauna Loa.
The crumbly, black stuff over a hard core is called "Aa" while
the smoother, ropy lava is "Pahohoe". The form the lava takes
depends on how fast is was moving when it cooled. |
 |
 |
In some places the lava jetted into the air and cooled before it hit the
ground. These vents (or Pu'u) are surrounded by cinder cones. |
 |
 |
Finally, when the eruption subsides, the lava drains back down inside
the volcano leaving a crater or caldera. |
 |
 |
Sometimes the cinders cover wide areas, giving a velvety look. Cracks
open up as the ground stretches due to movement deep underground. When the
lava flows around a patch of vegetation, sparing it, it is called a Kipuka. |
 |
 |
Kilauea is currently erupting, but Hawaiian eruptions are usually just
flows of lava, sometimes with jets, but are not the explosive eruptions
one finds elsewhere in the world. |
 |
 |
On our overflight we were lucky to spot a surface flow of hot lava.
Normally the lava flows through tubes that it creates under the surface. |
 |
 |
Finally it reaches the sea where it makes the Big Island just a little
bit bigger. |
 When
we drove through Volcanoes National Park, we drove around the main caldera of
Kilauea. The road goes down inside the caldera and over to the Halemaumau
crater.
 |
The floor of the crater has cooled enough that they now have
guided walking tours across the solidified lava. But don't breathe too
deeply near those vents! |
 |
 |
The wind was ferocious down in the caldera. The lava, the steam vents,
the struggling grasses gave it an other-worldly appearance. |
 |
Further around there were sulfur vents where yellow sulfur was deposited
by evil smelling fumes. |
 |
From the terrace of the Volcano House Hotel you could look across to the
steaming bluff. |
 |
This huge cinder cone was deposited by the 1959 eruption of Kilauea Iki
(at the time of my first visit to Hawai'i). |
|
