Week of Hurricane Irene and East Coast Earthquake? Who Cares? 8-26-11
***NOV. 10, 2012 UPDATE (New USGS Earthquake Findings, and Todays' Kentucky Earthquake Felt in NINE States) ***
We all should be aware by now, how devastating Hurricane Sandy, and the following nor-easter was to the East Coast and the NE U.S. and inland states as far as the Great Lakes. On Oct. 27th I wrote the following on my facebook page:
Geologists Find East Coast Quakes Travel Farther
"Scientists are confirming with empirical data what more than 50 million people in the eastern U.S. experienced firsthand: this was one powerful earthquake," USGS Director Marcia McNutt said in a news release about the findings presented at the Geological Society of America conference in Charlotte, N.C.
Researchers used landslides to see how far-reaching the shaking from East coast earthquakes could be. The unexpected jolt cracked the Washington Monument in spots and toppled delicate masonry high atop the National Cathedral. The shaking was felt from Georgia to New England.
According to the findings, the farthest landslide from the quake was 150 miles from the epicenter, a greater distance than any other similar-sized earthquake. Previous similar quakes have resulted in landslides no farther than 36 miles from the epicenter.
Additionally, the landslides from the 2011 tremor occurred in an area of about 12,895 square-miles - about the size of the state of Maryland. Previous studies indicated an area of about 580 square-miles - about the size of Houston - from an earthquake of similar magnitude.
"It's just much more dangerous to have an earthquake at that level back on the East Coast than it would be on the West Coast," said Edwin Harp, a USGS scientist and co-author of the study. "If something big happened, although it's much less frequent, it would tend to damage a lot more buildings because they're probably not quite up to the codes that they are in California."
Geologic structure and rock properties on the East Coast allow seismic waves to travel farther without weakening compared with the West Coast, Harp said.
He said equations used to predict ground shaking might need to be revised now that scientists know more about the power of East Coast earthquakes.
The information also will help with building codes as well as emergency preparedness, the USGS said.
While West Coast earthquake veterans scoffed at what they viewed as only a moderate temblor, the August 2011 quake changed the way officials along the East Coast viewed emergency preparedness. Emergency response plans that once focused on hurricanes, tornadoes, flooding and snow are being revised to include quakes.
Some states have enacted laws specifically related to the quake, and there is anecdotal evidence of a spike in insurance coverage for earthquake damage.
U.S. Geological Survey: http://www.usgs.gov/ Now, here is info on todays' Kentucky earthquake, felt in several surrounding states:
The USGS website says the epicenter of the 4.3 magnitude earthquake on Saturday afternoon was about 10 miles (16 kilometers) west of Whitesburg. Residents in nearby Virginia, West Virginia, Tennessee, North Carolina, South Carolina, Indiana, Ohio and Georgia also reported feeling the temblor.
National Weather Service spokesman Jeff Carico says employees at the office in Jackson, which is about 60 miles (100 kilometers) northwest of Whitesburg, felt the ground shake for about 15 seconds. He says the office has gotten numerous calls, but so far no one has reported any serious damage.
USGS geophysicist John Bellini says the quake is considered "light" and isn't expected to cause major damage.
I spoke with Evelyn Roeloffs, a USGS research geophysicist who has studied the effects of earthquakes on groundwater.
Evelyn Roeloffs: Generally, the main way they affect groundwater is that they cause the ground to expand and contract. And the seismic wave that these earthquakes generate actually cause the ground to expand and contract as they pass by. They can travel around the globe a couple of times actually and be recorded on sensitive seismic instruments. So, when those seismic waves pass through, you can see changes in groundwater levels.
Kara Capelli: Scientists and others have been noticing the effects of earthquakes on groundwater for a long time.
Evelyn Roeloffs: I think one of the neatest examples is from back in about 1952, when it was noticed that in a well in a shoe factory in Milwaukee, the water would slosh up and down every so often. And when they put a float recorder on there, and actually made a continuous record of the water level, they recorded things that actually looked like seismograms. And they saw that those variations were actually caused by seismic waves passing the well.
Kara Capelli: The most common effect on groundwater from earthquakes is an instantaneous water level increase or decrease. Recovery to the pre-earthquake level can be so rapid that no change is even detected. I also asked Evelyn about the effects of earthquakes on groundwater quality and quantity.
Evelyn Roeloffs: The spikes themselves, if you actually measure them quickly enough for actual oscillations, where they're making water move in and out of the aquifer and into the well, that can cause the water to become turbid or taste a little bit funny, which doesn't usually last more than a few days, at the most. Occasionally, it will happen that the groundwater level will go down and stay down or go up and stay up but usually not more than a foot or so.
And so, in the short run it might affect the amount of water you can get, depending on exactly where your pump is. But usually, those changes are small compared to the normal changes during the year associated with rainfall and temperature and stuff like that.
Kara Capelli: Though in general, these spikes have very little noticeable effects, sometimes groundwater very near to the epicenter of an earthquake can be permanently affected.
Evelyn Roeloffs: Closer to the earthquake, the effects can be much more severe. And one thing that has happened a couple of times in the U.S. is that the earthquake shaking shakes the hill up and fractures things a little bit and makes it more permeable, so that if people have domestic wells drilled near the top of the hill, they'll find that the water level in those wells may slowly drop. And then, at the same time, the flows in the streams that are draining the hill will increase.
And those kinds of changes really don't recover. They can result in changes of several feet or tens of feet of water. And so, it may cause a well to need to be deepened or even just abandoned. And this happened after the 1989 Loma Prieta earthquake in California near Santa Cruz. And there is also a case of this happening in Pennsylvania a number of years back.
Kara Capelli: The USGS Groundwater Resources Program monitors groundwater across the U.S. through real-time groundwater monitoring. This data can be found at waterdata.usgs.gov/usa/nwis/gw. And don't forget to follow the USGS on Twitter at twitter.com/usgs. I'm Kara Capelli for USGS CoreCast, a product of the US Geological Survey, Department of the Interior.
God only knows the changes in the earth what's going to happen with groundwater, sinkholes and buildings damaged from the earthquake, and after the storm. It's very surreal watching from the other side of the country, but personal experience has shown me that God rewards those who diligently seek Him. I'm seeing more personal blessings and individual blessings, and less blessings outside of a relationship with Jesus. Blessings are being whittled away from our nation as a whole, and increasing in individuals. What will become of our country where the blessings are on people who God chooses to personally bless, and takes away/or curses, the nation as a whole? I know. Who cares.
1 Kings 19:10-12
10He replied, “I have been very zealous for the Lord God Almighty. The
Israelites have rejected your covenant, broken down your altars, and put your
prophets to death with the sword. I am the only one left, and now they are
trying to kill me too.”11The Lord said, “Go out and stand on the mountain in the
presence of the Lord, for the Lord is about to pass by.”Then a great and powerful wind tore the mountains apart and
shattered the rocks before the Lord, but the Lord was not in the wind. After the wind there was an earthquake, but the Lord was not in the earthquake. 12After the earthquake came a fire, but the Lord was not in the fire. And after the fire came a gentle whisper...
Romans 1:24-25 Therefore God gave them over in the sinful desires of their hearts to sexual
impurity for the degrading of their bodies with one another. 25. They exchanged the truth of God for a lie, and worshiped and served created things rather than the Creator--who is forever praised. Amen.