Archipelago turning: New understanding of the ‘bend’ in the Hawaiian-Emperor archipelago

 The Hawaiian archipelago travels thousands of miles from its newest volcano off the Big Island to undersea peaks tens of millions of years old near the Aleutians, where it they are called the Emperor Seamounts.

If you look at a map of the Pacific sea floor, you can see the mysterious bend in the chain—the bend that separates the Hawaiian from the Emperor groups. (Image: The ocean floor of the North Pacific, showing the Hawaiian-Emperor archipelago as light blue dots on the darker blue ocean floor. Credit: University of Sydney.)

The Hawaiian part of the chain is younger, and is mostly islands. The Emperor seamounts are older and none reaches the surface. 

They are clearly part of the same chain, but that bend has been a mystery for decades.

Geologists believe the Pacific tectonic plate moves over a hot plume, which occasionally pops through the crust to form volcanoes. Thus the line of Hawaiian volcanoes can map the historical direction of the Pacific Plate’s movement. 

It has long been assumed that the bend in the chain has been associated with a change in the direction of the Pacific Plate’s drift, from generally north-northwestward more than 50 million years ago, to generally west-northwestward during the past 50 million years.

We covered that in this column in 2008.

But science moves on constantly, and what was accepted yesterday doesn’t necessarily get full credence today. 

One thing that remained confusing was that other chains on the Pacific Plate don’t show the same bend. So, if a change in the direction of the movement of the Pacific Plate affected the Hawaiian-Emperor chain, why would it not also have shown up on other long-lasting Pacific chains?

“The flow dynamics underlying the formation of the sharp bend occurring only in the Hawaiian–Emperor hotspot track in the Pacific Ocean remains enigmatic,” write the authors of a new study on the Hawaiian-Emperor bend.

In the new assessment, researchers suggest that two things were moving at once: The plate was on a generally unchanging west-northwest drift, but the underlying plume of molten rock was also drifting—in this case southward—until 50 million years ago. 

And since then, the plume has been generally stationary, allowing the plate drift alone to establish the pattern of the Hawaiian Islands.

Rakib Hassan, of the University of Sydney's School of Geosciences, was lead author in the study published in Nature, “A rapid burst in hotspot motion through the interaction of tectonics and deep mantle flow.” His co-authors are R. Dietmar Müller, Michael Gurnis, Simon E. Williams and Nicolas Flament. 

They are not the first to suggest that both the plume and the plate were in motion, but they used the power of a supercomputer to envision how it all works. 

To make sense of this, it’s useful to think of the globe as solid at the surface, molten in the middle and solid again at the core. Okay, that’s an oversimplification of a very complex process. The mantle, which lies below the surface crust of the Earth, is actually solid, but on geological time scales, it flows. Plumes of molten rock, which can poke through the crust to form volcanoes (Like Kilauea), rise from piles of rock deep in the mantle.

Here is how Science Daily described what Hassan and co-authors believe happened: “Between 50-100 million years ago, the edge of the pile under the north Pacific was pushed rapidly southward, along with the base of Hawaii's volcanic plume, causing it to tilt. The plume became vertical again once the motion of its base stopped; this dramatic start-stop motion resulted in the seamount chain's sharp bend.”  

This is difficult to envision. Imagine a kid flying a kite. The kite is the surface volcano. The wind is the Pacific Plate. The kite string is the plume and the kid is the base of the plume. 

As long as the wind is steady and the kid is standing still, the kite string bottom-to-top points straight downwind. But if the kid starts running to the left, perpendicular to the wind, the kite string points in a different direction—impacted both by the movement of the kid and the movement of the wind. The kite string will now point downwind and to the right. 

To understand the kite’s movement across the sky, you need to understand both the wind, and the kid.

Or, as co-author Müller said, “It is now clear that we first need to understand the dynamics of the deepest 'Underworld', right above the core, to unravel the history of volcanism at Earth's surface.”

The researchers used a great deal of computing power to model what they believe happened. A YouTube animation can be seen here.

© Jan TenBruggencate 2016

Kauai Joint Fact Finding: Now going after all farms, ranchers, even organic operators.

The county/state Joint Fact Finding group has finished its work and turned in a report that managed to satisfy no one.

Project manager Peter Adler predicted this a couple of months ago, when he said, apparently only half joking, “This report is going to give people a whole bunch of new things to argue about.”

The final report, if possible, is even more maddening than the draft report of a couple of months ago.

The draft report, at its very simplest, said three things: 1) the JFF looked hard but could find no evidence anyone has been harmed by the agricultural chemicals used by the seed companies and Kauai Coffee; 2) the data aren't very good; and 3) the data need to be better.

The final report says even less. Despite having looked at dozens upon dozens of reports, peer-reviewed science and not, government studies and raw anecdote, the JFF now says it can’t even say even that it found nothing. Because nothing is, after all, the absence of something—but nothing doesn’t mean there couldn’t be something.

So, the JFF announced that it couldn’t find either something or nothing, period.

"Currently there is not enough information to conclude if pesticide use by the seed companies plays any role in the health of Kauai`s residents," the JFF said.

Thus, fundamentally, the JFF concluded that anybody who said people were harmed or not harmed by pesticides was lying. It said there wasn't information to say, either way, so anybody who opined was doing so without a basis for that opination.

If this is sounding a lot like Alice in Wonderland or a Billy Preston song, well, there you go.

Was there a useful message in the JFF report? Perhaps yes.

The JFF members betrayed themselves as true believers. This no surprise. Several of them have said so to me personally, and to dozens of other people at public meetings. They said that although they looked very hard and found nothing, they really believe there must be problems with pesticide use—and not just in the big seed and coffee farms.

In the report, they cite all kinds of situations and studies in other states and other countries. And they extrapolate to Kauai, even in the absence of local evidence of harm. And so they recommend an unprecedented level of new regulation and investigation. We in Hawai`i need to be at least or even more heavily regulated than any state in the union, they argue.

They seek to test the blood and urine of pesticide applicators, field workers, and the blood and urine of school children.

Having failed to find hard evidence on the seed industry, the JFF now wants to expand new regulatory oversight to “any farm that produces food products.” Yes, they’re going after organic farms, after taro farmers, after beekeepers, after livestock operators, after everybody. (That’s on top of all the regulatory oversight all those people already face.) Here's the actual language, from page 96: "more data and better reporting on pesticide use by all pesticide users, including smaller conventional farms, organic farms, or any farm that produces food products."

They want to add new fees on all pesticide use by everybody—which at a minimum will raise costs for everyone, and will likely make Hawai`i’s food more expensive or make farming less profitable or both.

They want the Department of Health to monitor surface waters for pesticide contamination, and also want the Department of Land and Natural Resources to conduct surface water monitoring at wetland habitats. You might reasonably wonder at having two different organizations, funded by the same taxpayers, doing the same kind of testing.

They want the Department of Health to conduct general air monitoring, but the Department of Education to also conduct school air monitoring. You might once again reasonably wonder at having two different organizations, funded by the same taxpayers, doing the same kind of testing.

They also want testing of feral animals, birds and marine life.

The state has already agreed to do some new testing, new regulation, new pesticide use disclosure statewide and so on, but the JFF report seeks even more.

It is too late now to fix the document, but we are reminded of Slick Willie Sutton’s response to why he robbed banks: “Because that’s where the money is.” The reverse, also true, is that you don’t rob places where the money isn’t.

Does it make sense to set up a whole list of mandatory, major, permanent, costly, sometimes duplicative government regulatory programs where there is no evidence of a problem? Slick Willie would argue against that, I think.

Which is not to say that JFF did a bad job. Just that the members missed a key piece of the logical puzzle when they leaped right from “no evidence” to “enact robust regulation.”

Let’s assume a driver approaches a mechanic and says, “My car’s broken. I mean, I think it’s broken. Well, I actually don’t know for sure that it’s broken, but cars break down everywhere, so it might be broken, and I’m satisfied that it could be. Anyhow, please fix it.”

You can image the mechanic’s response, “Well, I can certainly do it, but this is going to be real expensive and it’s going to take a long time. And you’ll need to leave a large deposit.”

He'll find something to fix, but it may not be the thing that was wrong.

© Jan TenBruggencate 2016

Reef corals at risk from climate change, acidification--can science help?

If you leave something with a hard surface in the tropical ocean long enough, coral will settle and grow-whether it’s a set of lost keys or eyeglasses or a rock.

I’ve found coral growing on glass fishing floats and pieces of marine debris—even plastic rope. It would suggest real resilience on the part of corals, but increasingly, they seem to be suffering.

(Image: On a pink background of corraline algae, two just-attached coral juveniles form circular shapes, while a white larval coral swims by. Credit: Hollie Putnam.)

 

But there’s a lot we don’t know about corals, and with coral reefs at risk due to climate change and ocean acidification. Hawaiian researchers are doing some of the seminal work needed to better understand some of the issues involved. We’ll look at two of those efforts here.

In an article in the Proceedings of the Royal Society B/Biological Sciences, authors found that there are certain genetic switches that change during a coral’s life.

When coral is in larval form, free-floating, it doesn’t produce a limestone skeleton. Only after it lands on a surface does the genetic switch change positions, and it starts building rock.

“Our research on reproduction in the lace coral, Pocillopora damicornis, provided the perfect opportunity to look at a natural on-off switch in coral biomineralization,” said co-lead author Hollie Putnam, of the Hawai`i Institute of Marine Biology (HIMB).

A team of researchers from University of Hawai`i, Rutgers and the University of Haifa studied that process. A press release with more images is here. 

The paper has the painful title, “Temporal and spatial expression patterns of biomineralization proteins during early development in the stony coral Pocillopora damicornis.” The authors are Tali Mass, M. Putnam, Jeana L. Drake, Ehud Zelzion, Gates, Debashish Bhattacharya and Paul G. Falkowski.

“The better we understand how corals grow, the better we understand the way they respond to ocean acidification, rising sea surface temperatures and pollution, and can therefore forecast and manage reefs communities in the future,” said Ruth Gates, director of the Hawai`i Institute of Marine Biology.

 

Another feature that’s important for a marine reef’s survival during climate change is its genetic diversity. A team led by HIMB researcher Kimberly Selkoe looked into the genetic diversity of reef corals by taking more than 17,000 samples from 47 Hawaiian coral species.

 

(Image: Coral reef with fishes in the Papahānaumokuākea Marine National Monument. Credit: James Watt, courtesy of PMNM/NOAA.)

Their work was also published in the Proceedings of the Royal Society B. A University of Hawai`i press release on the work is here. The paper is entitled “The DNA of coral reef biodiversity: predicting and protecting genetic diversity of reef assemblages.”

The authors are Selkoe, Oscar E. Gaggiotti, Eric A. Treml, Johanna L. K. Wren, Mary K. Donovan, Hawai‘i Reef Connectivity Consortium and Robert J. Toonen. They hail from HIMB, the University of California Santa Barbara, University of St. Andrews in Scotland, and the University of Melbourne in Australia.

The research team looked at reefs on 13 Hawaiian islands in both the main Hawaiian Island group and the Northwestern Hawaiian Islands. One finding: areas with higher species diversity—more different kinds of corals—also had corals with greater internal genetic diversity.

They also found that certain reefs, ones that had been bleached due to warm water temperatures, tended to have lower genetic diversity.

“This negative impact of thermal stress on genetic diversity suggests that climate change will compromise the adaptive capacity and genetic integrity of not just corals but the entire coral reef community,” Selkoe said.

There’s an assumption that more genetically diverse reefs have a stronger capacity to respond and survive threats like warming and acidification of the oceans. The research team will be looking into that, and whether the pattern of species diversity with genetic diversity is confirmed. 

“If these relationships can be confirmed and replicated elsewhere, DNA sampling may one day allow rapid assessment of species diversity and new metrics of resilience and adaptive capacity,” Selkoe said.

The authors make the point that one technique for preserving coral reefs is to establish reserves to protect the areas with the greatest species and genetic diversity.

“The results highlight inherent feedbacks between ecology and genetics, raise concern that genetic resilience of entire reef communities is compromised by factors that reduce coral cover or available habitat, including thermal stress, and provide a foundation for new strategies for monitoring and preserving biodiversity of entire reef ecosystems,” the paper says.

But there’s still a lot to know. One question is why coral species diversity is linked to genetic diversity. One suggestion is that it may have something to do with the kinds and numbers of coral-eating fish that are in the area. The researchers did find that where there are more vegetarian fish (herbivores), there are more corals—is that just because there’s more food and shelter there, or something else. 

One bit of good news for Hawai`i is that coral bleaching due to unusually high water temperatures, while a problem here, is a much worse problem on reefs closer to the equator.

“Low-latitude Pacific reefs have experienced thermal stress up to 240% higher than Hawai‘i and documented ecological effects have also been more severe, suggesting that recent declines in genetic diversity might also be more severe at lower latitudes,” the authors write.

© Jan TenBruggencate 2016

Of science, mulberries and Leonardo da Vinci

There is a lot to be said for figuring things out.

Which is to say, something very different than what we find in a lot of our public discourse. Likes and copying links are cheerleading, not informed conversation.

Figuring things out is science: You have problem, you test and probe and try looking at it from different perspectives, and you try to develop a solution. And then you test the solution.

Picking berries off my mulberry tree, I was frustrated that I’d circle the tree clockwise and pick every ripe berry I saw, then turn around and see there were lots more I’d missed.

So I went back around and picked counterclockwise, now seeing berries that had previously been hidden by leaves. 

But there were still unpicked berries. How was I missing them? I went into the canopy and looked out, and now there were more ripe berries that had been hidden from the outside, but visible from the inside. 

To do a good harvest, I needed to also pick backwards and inside-out. Look at things from different perspectives.

I’d figured something out.

(Image: Mulberries on teak leaves in a blue bucket.)

 

Which recalls the Codex Leicester, Leonardo da Vinci’s 72 page reflection on stuff he’d figured out in the early 1500s. Microsoft’s Bill Gates in 1994 paid $30.8 million for the Codex—more than anyone had ever paid for any book.

If you could afford it, and he could, why wouldn’t you want to own a document half a millenium old, and by, well, Leonardo da Vinci? 

(Image: A page from the da Vinci document sometimes known as Codex Leicester, sometimes Codex Hammer, which perhaps now ought to be Codex Gates. Credit: Leonardo da Vinci.)

I keep a warm thought for Bill Gates, because on top of all the tech and charitable work he does, he took the codex, scanned it and made it available to the world.

Leonardo Da Vinci was and is best known as a painter (“Mona Lisa,” “The Last Supper")

But he was also one of the most figure-it-out people our little blue planet has ever produced.

In the Codex, among diverse other things, he figures out earthshine. This is that dim image of a full moon you see when the moon is in crescent. It is caused by the sun’s reflection off the earth—earthshine. It was proven a century later, but he figured it out and wrote about it.

NASA talks about that, crediting da Vinci with “a wild kind of imagination…one thing Leonardo had in abundance.”

One of the cool things about the Codex is that da Vinci wrote it in mirror script—he wrote it inside-out and backwards. Was it code to make it harder for others to read, or did he simply have the left-handed kind of brain that made it easier to write that way? That’s still debated.

I doubt that this was his message, but he might have been trying to say that you need to look at stuff inside out and backwards if you’re going to understand it.

We need more of that kind of thinking.

© Jan TenBruggencate 2016