Elaine Meinel Supkis
Scientists have connected plankton blooms that occur in subduction plate zones with earthquake events. This is another clue for predicting earthquakes. Just like before a thunderstorm, many creatures can also sense an impending earthquake's manifestations.
Concentrations of the natural pigment chlorophyll in coastal waters have been shown to rise prior to earthquakes.
These chlorophyll increases are due to blooms of plankton, which use the pigment to convert solar energy to chemical energy via photosynthesis.
A joint US-Indian team of researchers analysed satellite data on ocean coastal areas lying near the epicentres of four recent quakes.
With the oceans warming, it is increasingly common to have sudden population surges. But it seems, thanks to satellite photos, very specifically local blooms come out of a very small area which is exactly the same area where a subsequent quake occurs.
The authors say the chlorophyll blooms are linked to a release of thermal energy prior to an earthquake.
This causes the sea surface temperature to rise and increases the surface latent heat flux - the amount of energy moving from the surface to the air due to evaporation.
And in turn, there is enhanced upwelling - the process by which cold, nutrient-rich water is transported from the deep sea to the surface.
Heat does rise whether it be water or air. But here is a puzzle:http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2005/07/12/MNG8SDMMR01.DTL">San Francisco Chronicle:
Glen Martin, Chronicle Environment Writer
Tuesday, July 12, 2005
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Oceanic plankton have largely disappeared from the waters off Northern California, Oregon and Washington, mystifying scientists, stressing fisheries and causing widespread seabird mortality.
The phenomenon could have long-term implications if it continues: a general decline in near-shore oceanic life, with far fewer fish, birds and marine mammals. No one is certain how long the condition will last. But even a short duration could severely affect seabird populations because of drastically reduced nesting success, scientists say.
The plankton disappearance is caused by a slackening of what is known as "upwelling:" the seasonal movement of cold, nutrient-rich offshore water into areas near shore.
This cold water sustains vast quantities of phytoplankton and zooplankton, which are the basis of the marine food web. During periods of vigorous upwelling and consequent plankton "blooms," everything from salmon to blue whales fattens and thrives on the continental shelf of the West Coast.
Far from plankton upwelling, it is doing the opposite. But not because the water is getting colder. Scientists don't know what is going on except the water is defintely warmer and the cycling of very deep water with the upper currents isn't happening and this is an ongoing crisis on the West Coast. So maybe it is the same thing?
Perhaps, unlike the upwelling of plankton before great quakes in Asia, we see the opposite here? Namely, the warm water below simply is heating up the waters above? An interesting thing to explore. We do know something big is going on very deep in the ocean trenches and the trenches are where the main "warfare" is going on as the plates battle for space.
One the geologically more stable East Coast, we have been having serious algae blooms this spring. Chronicle.com:
May 2, 2006, 7:26PM
Toxic Algae Bloom Returns to Maine Coast
© 2006 The Associated Press
PORTLAND, Maine — The red tide, which shut down much of the Maine coast to shellfish harvesting last year, is back. Red tide has now shut down harvesting in an area near Harpswell from Dickson Point to West Cundy Point. Shellfishermen say they hope the shutdown doesn't spread like it did last year.
"We're all worried," John Lyon, a clam digger, told WCSH-TV. "We don't want another year like last year."
I heard this on the radio and thought, this is becoming common, isn't it?
A study this year by the Woods Hole Oceanographic Institution in Cape Cod, Mass., shows little threat in southern New England but more cause for concern in Maine.
Microscopic cysts dropped by toxic algae blooms on the ocean floor act like seeds for future red tide outbreaks. Despite the intensity of last year's bloom, the cysts are far less widespread than expected on the southern New England sea floor, Wood Hole scientists said.
While researchers found an average of 10 to 40 cysts per cubic centimeter of sediment off the Massachusetts coast, some Maine concentrations remained in the 1,000 to 6,000 range.
But scientists caution that cysts are only one of a variety of factors needed for a crippling red tide. Other factors include weather patterns and ocean currents.
And now one can add, subduction earthquake heating.
Here is another take on algal toxic blooms: Woods Hole:
One question that scientists ponder is "Are HABs spreading and is the problem getting worse?" A growing body of evidence suggests that HABs are increasing around the globe.
Maps of the expansion of HABs in the US since 1972 indicate the scale of the problem now compared to 30 years ago. We have more toxic algal species, more algal toxins, more areas affected, more fisheries resources affected, and higher economic losses.
Why is this? There are many reasons. The first thought of many is that pollution or other human activities are involved. On close inspection, however, many of the "new" or expanded HAB problems in the US occurred in waters where pollution is not an obvious factor. The organisms responsible for HABs have been on earth for a long time, so new bloom events may simply reflect better detection methods and more observers rather than new species introductions or dispersal events. The 1987 NSP event in North Carolina is a good example, as that was a Florida bloom carried by the Gulf Stream to North Carolina waters - a totally natural phenomenon with no linkage to human activities. Likewise, a massive 1972 red tide was responsible for introducing dormant cysts of the PSP-producing species Alexandrium tamarense to southern New England waters, where it has persisted to this day. Those coastal waters have seen an increase in pollution over the years, but the actual introduction and colonization of the species is the result of natural currents and environmental forcings, including a hurricane which occurred immediately prior to the 1972 bloom. It may be that subsequent blooms of this species are enhanced by pollution, but this has not yet been demonstrated. The appearance of ASP along the west coast after 1991 is also not a result of pollution, but rather to communication among scientists and improved chemical detection methods that led to the identification of a toxin that was surely present in those waters for many years. Some believe that man may have contributed to the speading problem by transporting toxic species in ship ballast water, but this also remains an unproven hypothesis in the United States with respect to HAB species. Another causative factor is that we have dramatically increased aquaculture activities, and these lead to increased monitoring of product quality and safety, revealing indigenous toxic algae that were probably always there.
I noted last summer the various blooms occuring in the Gulf region immediately before the four biggest hurricanes hit. Human pollution is destroying aquatic environments, no ifs ands or buts. Nonetheless, the "natural" expansion of these events isn't due to direct pollution but indirect via the greenhouse effect.
We seem to be in a cycle where both the earth is heating things up and so is the sun and humans are alteraing the ratios of various gasses. Altogether, an unsettling time.