Friday, January 22, 2010

Magma pressure flat lines ~ The Hawaiian Hot-spot ~ Vog… again

Deformation graphs are displaying new territory: a virtually total lack of magma pressure. If this were a heartbeat monitor we would be hearing that dreaded sustained tone of a flat-lining patient. But of course this is Pele and she has been creating island after island right here at this location for an estimated 80-million years and is not likely to stop anytime soon.

The Hawaiian Hotspot (Excerpts from my new lava photography book being published now):
The Hawaiian Hotspot is a weak section within the Earths mantle that allows magma to plume, or slice the Earth’s crust. The islands of Hawai'i are riding atop the Pacific Plate: the oceanic tectonic plate beneath the Pacific Ocean. The Pacific Plate is the seafloor and in Hawai'i it is constantly moving in a northwesterly direction at an average of 49 miles per million years (about 3 or 4 inches per year).

As the Pacific Plate moves along, the hotspot has formed landmass after landmass - creating this chain of islands named the Hawaiian Archipelago. The Hawaiian Archipelago is a volcanic ridge of islands and atolls approximately 1,600 miles long. When we include the underwater portion of this contiguous chain of ridges it is then named the Hawaiian-Emperor seamount chain and the length becomes nearly 3,600 miles, and many millions of years in the making.

Here, under my house, under this Big Island, the Hawaiian hotspot is permanently stationed. Oddly, the location of this upwelling of magma through the mantle does not change; it does not move off with its northwesterly parade of islands. Instead it continually slices like a laser of inner molten earth up into, and through, the Pacific Plate itself. This nearly continuous pluming of magma slowly creates underwater volcanoes that can eventually reach the ocean’s surface at up to 19,000 feet above the seafloor - just as the Big Island has - thus forming the next island in the chain.

From the perspective of humans and linear time, this birthing of islands is a very long and drawn out process. The Hawaiian hot spot has been building islands, atolls and seamounts for about 80 million years. The spectacularly sculptured-by-time Na Pali Coast Mountains of Kauai, our eldest island neighbor situated 250 miles to the northwest, were formed on this very hot spot about 5 million years ago. Only 3,000 feet below the ocean surface a new seamount volcano is erupting just offshore 26 miles south of my home and is already named Lo'ihi… the next Hawaiian Island…

Hawaiian Volcano Observatory’s (HVO) Jaggar webcam reveals the lack of wind this morning I am also seeing here at my house; and with it, the widespread vog in all directions.

Reports from the active lava flow fields as viewed from the end of highway 130, the Hawaii County viewing area, are bleak. Only a few small, glowing, lava spots could be seen on the pali far away; likely a result of the surface lava being reduce by this current deflationary stage.

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