Researcher Says the Hawaiian Islands Are Dissolving

SternisheFan writes with a snippet from Science Recorder: "Reporting in the journal Geochimica et Cosmochimica Acta, researchers at Brigham Young University say that the Hawaiian Islands are slowly dissolving. Eventually, Oahu's Koolau and Waianae mountains will dwindle to little more than a flat, low-lying island like Midway. While erosion is certainly a guilty party, researchers contend that the mountains of Oahu are, in fact, dissolving from within. Researchers spent several months collecting samples of groundwater and stream water to determine which source removed more mineral material. They also put to use surface water estimates from the U.S. Geological Survey to calculate the quantity of mass that vanished from the island each year. Researchers point out that Oahu is actually rising in elevation at a slow but steady rate due to plate tectonics. [BYU geologist Steve Nelson] and colleagues believe that Oahu will continue to grow for as long as 1.5 million years. Beyond that, the force of groundwater will eventually win and Oahu will begin its transformation to a flat, low-lying island like Midway." (If you have journal access, or don't mind forking over $40, you can read the original paper.)

Comments

Oh Shit

[binarylarry]

Larry Ellison isn't going to like this...

Re:Oh Shit

[davester666]

That's fine because he won't let it be stored in anything but an Oracle database, running an Oracle OS on Oracle hardware. It'll never be big enough to hold his entire ego, and it certainly won't last the decade...

Hmmmm

[Dishwasha]

colleagues believe that Oahu will continue to grow for as long as 1.5 million years.

So what you're saying is, we've got some time?

Of course

[jfdavis668]

This is how islands form and erode. This is some kind of surprise?

Re:Of course

[Anonymous Coward]

I figured that islands erode from the ocean waves beating on them, not from groundwater dissolving the rock inside of it.

Re:Of course

[houghi]

While erosion is certainly a guilty party, researchers contend that the mountains of Oahu are, in fact, dissolving from within.

Erosion is not the interesting part, From within is.

Re:Of course

[Anne_Nonymous]

>> the sky is expected to remain blue and scientists predict that water will remain wet

Your misguided promotion of the radical scientific agenda won't fool Jesus.

Re:Of course

[PlusFiveTroll]

Seamount style landmasses do not tend to get built up, unlike continental land masses (which still erode way more then they gain from the sea, just more slowly). The steep sides tend to deeply deposit any eroded materials. Once the island is below sea level the most of the most active erosion ends and the island slowly sinks back in to the lithosphere until the time it is finally drug back in to the earth in a subduction zone.

The Hawaiian islands do get a lot of rainfall in most places each year, the nature of its porus volcanic soils is especially dissolvable to fresh water.

Re:Of course

[Anonymous Coward]

Seamount style landmasses do not tend to get built up, unlike continental land masses (which still erode way more then they gain from the sea, just more slowly). The steep sides tend to deeply deposit any eroded materials. Once the island is below sea level the most of the most active erosion ends and the island slowly sinks back in to the lithosphere until the time it is finally drug back in to the earth in a subduction zone.

The Hawaiian islands do get a lot of rainfall in most places each year, the nature of its porus volcanic soils is especially dissolvable to fresh water.

The rainiest spot on earth is on Kauai. Hawa`i receives so much rain because of the mountain heights. The mountains force the moisture-laden air up where it can't keep all that water. This is what causes the leeward side. As an example, the North Shore of O`ahu is wet, but Honolulu side doesn't even receive a quarter of the rain. Once the mountains sink, nothing will force the air to give up the moisture as rain.

Here's what I don't get

[Anonymous Coward]

In the 70s, all people heard was "save the oceans!" and such. Now, we're making MORE ocean and people are still upset. We just can't win.

Re:But this is wrong.

[bmo]

But we already know that subsurface groundwater causes erosion.

We've known for a long time. We have national parks dedicated to pretty examples of this. Insurance companies hate extreme examples of this like karst topographies, especially when a house falls in a sinkhole.

Somehow someone thought that this didn't apply to islands and needed a study to find this out? How do I get a grant to do a similar study in another tropical paradise to prove the obvious?

--
BMO

Re:But this is wrong.

[bmo]

An interesting result would have been "strangely, groundwater doesn't cause erosion here" because groundwater causes erosion everywhere.

Even here in New England, groundwater does a bang-up job of dissolving the iron out of granite and producing what is known as "rotten rock" and causing bathtub-rings of rust in ISDS test pits that make seasonal water table estimations easy. Water also dissolves out feldspars giving the classic pitting of granite rocks.

This wasn't interesting in the least. "Yup, groundwater is causing erosion here too." Wow.

Show me where water doesn't cause erosion. THAT would be pretty cool.

--
BMO

Re:Could someone tell me

[reboot246]

It's an atoll. It's barely above water.