Subduction zones and earthquakes

I am still waiting to hear from a couple friends in Japan, and I hope to hear that they and their families are safe. There are also extensive fears about nuclear radiation, as well as problems with evacuations and shelter for those displaced, throughout the Tohoku region. There are many good resources for information on these factors, so I will not focus on them.

Instead I will focus on the geological effects of this earthquake, since I understand these a bit better.

The 8.9 magnitude earthquake has shifted the Earth of its access by about 16.5 cm. This will cause the planet to rotate faster and shorten the length of the Earth's day by 1.8 millionths of a second or so. It has also moved the coastline of Japan in the Tohoku region by about 4 m to the east in some regions.
The cause of this earthquake is due to the subduction zone which lies to the east of Japan (the thick line to the east of the epicenter on the image below). The Pacific Plate is being subducted, or pulled under, the North American Plate, on which Japan lies. The motion of the scraping of the two plates together builds up strain energy which then must be released at some indeterminable period. The release of the strain results in an earthquake, in this case a very large earthquake.

When the movement of the Earth occurred underwater, it displaced a large bit sea water and thus created the large tsunami which hit the coastal regions of the Tohoku region. The Pacific Plate's maximum westward movement was about 20 m, with the movement along the fault reducing as you go away from the epicenter. This is also why the amount of shaking and damage decreased away from the epicenter and fault.





BBC - How the quake has moved Japan

Mediterranean Sharks Resulted from Wrong Turn

A new study involving Mediterranean great white sharks suggests that they are more closely related to sharks from Australia and New Zealand, and less similar to those of the Atlantic Ocean as previously thought.  It is believed that the group of Mediterranean sharks arrived about 450,000 years ago after making a "wrong turn" on their return to the location of their birth.  This period of time was an interglacial period, in which extreme current variations were occurring.  The change in warm and cold currents may have been significant enough to alter the course of the migrating sharks.  If only a few shark pups were born in the Mediterranean waters, the study indicates that this would be all that was needed to begin a new cycle of migration to the same location for future generations.  This is an interesting study which may have implications for other species migrations during interglacial periods.

Methane Seeping from Arctic Sea-beds

From the BBC: Methane seeps from Arctic sea-bed

Scientists have found that methane, usually trapped within the Arctic sea-bed as a "methane hydrate," an ice-like substance compose of water and methane, which is stable under high pressure and low temperature conditions, is being released from the seafloor sediment. This hydrate breaks down as temperatures rise, and "bubbles" of methane rising from the seabed indicate unstable conditions for this hydrate.

Thirty years ago, the methane hydrate was stable at depths as shallow as 360m, but recent data suggests it is now stable in depths over 400m. Temperature records indicate that the temperature in the sea off of Norway, where more than 250 plumes of methane bubbles are being released from the seafloor, has increased by 1 C during the past 30 years.

Scientists have noticed that the area of interest has been experiencing climate change at a rate faster than many other places in the world. It has been thought for a long time that if the oceans warm, hydrates within the sea floor may be released and contribute a positive greenhouse effect. The current research is attempting to determine whether this is something that's occuring in the region off of Norway in a relatively short timescale. Methane is released from the ocean floor elsewhere at higher temperatures and lower pressures, so it's possible that this has been occuring near Norway since the end of the last ice age.

The significant implications of this research are that the warming climate is causing methane to be released from more and deeper areas of the Arctic Ocean. The team wants to research further to observe the methane plumes and to determine their effect on the ocean and ultimately the atmosphere.

Climate Change Impact

I found the article Low Flows, Hot Trout through the Big Sky Institute, which focuses on the Clark Fork Basin in Montana and how climate change affects the area: through increasing temperatures, earlier snowmelt, increased chance for wildfires, and impact on wildlife. The in-depth scientific analysis of climate change and what it means for the Clark Fork area can be applied to other areas facing similar problems, such as Yellowstone, Idaho, or even Bozeman. When I went to the USGS office in Boise, ID, for database training in groundwater programs, I was introduced to biological studies going on there in terms of trout and other fish, and their findings directly relate to this study.

CBM Discharge and Storm Flows

I found the report on Water Resource Monitoring of Streams in the Coal Bed Methane Production Area of the Powder River Basin, Wyoming to be interesting since it analyzes coal bed methane (CBM) discharge during storm flows, and particularly during a period (2001-2006) of drought in the watershed areas investigated.

CBM is not a topic on which I have a broad knowledge, but it is important in the Wyoming and Montana areas as a source of energy. The environmental effects of CBM wells is of particular interest to an environmentally conscious population. I participated in storm sampling with the USGS during some particularly intense (for San Diego) storms and found it to be an interesting (and wet) study, but I wasn't able to delve into the subject since my main responsibility was ground-water sampling.

It's a fairly lengthy study, but the end result concludes that, in general, there is little effect from CBM discharges on storm flow chemistry, which agrees with much of the available information that states that CBM-discharged water has little effect on the environment into which it is discharged.

Water Rights and Budget Cuts

I found this article on the US Water News wesbite, regarding Idaho's Comprehensive Aquifer Management Plan (CAMP), a plan which will cost $100 million in its first 10 years. The plan to manage the Eastern Snake Plain Aquifer in Idaho faces serious problems with current budget cuts due to a poor economy.

Boise, Idaho

The Eastern Snake Plain Aquifer provides drinking water for about one third of Idaho’s population in the eastern part of the state. Most of the water is used for agriculture, irrigating about 60% of Idaho's total irrigated acres. About half of the irrigation water is
ground-water, and the other half is surface water.

Drought and extensive ground-water pumping over the past half century have depleted this aquifer and resulting in lawsuits over water rights between surface and ground-water users. The plan intends to recharge the aquifer and to change how the water is used to resolve these disputes and preserve a vital aquifer for the eastern part of the state.

The real trouble faced by this plan is whether or not it will be passed. Extreme budget cuts threaten to prevent this measure from being passed, as it calls for $3 million per year to come from the state. The plan has been approved by the Water Resource Board, and now it must be passed by the Legislature.

The plan is a culmination of the cooperation among water users, agency staff, and consultants to create a feasible water management solution for the aquifer in both the long-term and the short-term.

Gas-Guzzling Bacteria

I found an interesting article while surfing, about bacteria that oxidize methane and can reduce the amount of methane in soils (http://www.brightsurf.com/news/headlines/17905/Gas-guzzling_bacteria.html). Under atmospheric conditions in well-drained soil, the bacteria can reduce methane in soil by 10 percent.

The bacteria was detected using a new method involving stable carbon isotopes and allows scientists "to track where carbon is incorporated into bacteria at the low atmospheric levels of methane in soils."

The bacteria can be used to maximize the amount of atmospheric methane oxidized by soils, and may help deal with the increased level of methane in our atmosphere today.