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Updated: 14 min 21 sec ago

First to arrive and last to leave…

Sun, 08/23/2015 - 18:17
It is hard to believe that just a few days ago, the hotel had 30+ college students
roaming the hallways and the parking lot was full of SUV’s washed in clay, sand and
mud. When most of the second phase of the SUGAR project had come to a halt, there
was still work to be completed by the Seismic Source Team (SST). In order to
understand why, let me take you through the work schedule of the SST.
Dr. Harder and I drove to Atlanta on July 1st after completion of the ENAM
project in North Carolina and began scouting the shot-holes we would need to drill, load
and stem i.e. fill before the shot dates, which were scheduled for August 7th and 8th for
Line 2 and August 14th for Line 3. When scouting, you want to ensure that the shot-hole
locations selected have good, accessible roads and enough space for the drillers as well as
work crew to move in and out of easily. However beforehand, you want to ensure that
you have the permits to access different properties and have the correct keys for the
property entrance/exit gates, which Donna took care of. Scouting holes took 4 days
before drilling began on July 7th until July 29th.
An example of a good, accessible road for the drillers and SST to use.Pick a lock, any lock. One of the entrance/exit gates to a shot location. Thankfully, we
had the key. I just had to test it on each lock to open the gate. A typical workday would consist of waking up at 6:30 am, eating breakfast at 7
am and leaving to work at 7:30/8 am. We would arrive on site about an hour later and the
drillers would set up and begin drilling. This would take about 2-3 hours at some holes
and 3-4 hours at others. The last hole composed of hard rock took about 14 hours to
complete. That does not include the time it took for us to stem the hole. We would
prepare the charges to load into the hole when the drillers had ~20 ft left to drill. They
drilled up to ~80 ft at the 2 shot-holes on the ends of Line 2 and ~70 ft for the remaining
13 shot-holes. For Line 3, they drilled all 11 holes to ~60 ft. After drilling and loading
the charges into the ground, Dr. Harder would lead the drillers to the next shot-hole while
Galen, Yogi and I would stay behind to stem the hole with gravel, sand and plug it with
bentonite. We would also check the detonators to make sure they worked before heading
off to the next shot-hole to repeat the process. On average, we would drive anywhere
from 100 – 200 miles per day depending on what we were doing and where we needed to

Yogi (Victor Avila, left) and Galen preparing 2  charges to be lowered into the shot-hole. Each charge contains 2 detonators attached  to 2 boosters indicated by the sets of wires.The drillers lowering the charge into the hole with Yogi carefully holding the detonator (orange wire) chords. On the left is the water truck and to the right is the drill rig."The Beast" with a 1.1 Explosives placard after transporting the source materials to the shot location.Galen taking a GPS waypoint of the loaded shot-hole while Ashley tests the detonators to ensure that they are working.Dr. Harder (left) and Kent splicing the wires at one of the shot-holes to connect the detonators in order to shoot. The routine changed once drilling was complete. We made our way to Vidalia
where we met with Donna, Dan and everyone at the instruments center and began
preparing our equipment for the nights we were going to shoot. Shots would start at 11
pm and last until as late/early as sunrise depending on the weather conditions as well as if
the detonators would connect. The days that the deployment team members were
flagging and deploying instruments, we were busy driving to shot-holes and cleaning the
ones that blew out. The idea is that you make the shot-hole location look the way it did
before the shot took place.
Shot-hole 7 on Line 3. It looks like a regular hole, but it is actually about 5ft deep and has a 5ft diameter cavity.Using the backhoe to clean up the above shot-hole.After clean up!!
I can honestly say there was never a dull moment while working on the SST. I
remember Donna saying at our farewell dinner something along the lines, “We do all this
work for just a disk of data, but it’s all worth it.” She could not have summed it up any
better than that.

Here’s to another successful project….salud!

Ashley Nauer - UTEP


Sun, 08/16/2015 - 22:33
... so my mother can see I'm wearing a hardhat (Hi Mom).  Galen getting done, Natalie with commentary, Yogi counting it down ...

Shot L3-01 video

Sun, 08/16/2015 - 21:52

HUGE THANKS to all the volunteers who worked so hard to make this project such a great success. It  was a pleasure working with you and getting to know you all.  Also mega thanks to all the landowners who were kind enough, and trusting enough, to let us put a source on their property.  None of this could have happened without your generosity and spirit of curiosity.  Thanks so much.


What goes bump in the night? We do.

Sun, 08/16/2015 - 11:30
Controlled blasts in deep holes are the source of sound waves for our program.  We set them off in the middle of the night because that is when it is quietest along the county and state roads where our instruments are shallowly buried on profiles across eastern Georgia and listening for sound waves.  During the nights of Aug 7, 8 and 11, our blasting experts Steve Harder, Galen Kaip and Ashley Nauer prepped and detonated 25 blasts along our lines, with some help from other enthusiastic scientists (like me).  Our shots have between 200 and 1600 lbs of explosives – mostly ammonium nitrate emulsion. At each shot, we connect a long wire between the drill hole and a blast box, move back a safe distance from the shot site, wait for the appointed time, and set off the blast. The blast box is used to detonate the shot at a very accurate time. There were two shooting teams, and each has different time windows for blasting to ensure that we only do one blast at a time. If two blasts occurred at the same time, the sound waves could interfere with one another.
Ashley Nauer and Kent Anderson wire up a shot.
When the blast goes off, you feel it more than hear it.  The sound waves radiate out from the shot traveling both within the earth and along the surface. Waves that travel along the surface of the earth (“surface waves”) cause the most ground shaking. If the ground is wet, sometimes a geiser briefly occurs 5-10 seconds are the explosion.  Not surprisingly, plenty of people are interested in experiencing this besides us!  Several of the property owners who very kindly gave us permission to set off these blasts on their land came out in the middle of the night to spectate.
Even putting aside the obvious rush of setting off a bunch of blasts, its fun to be out and about in the Georgia country side at night.  A cacophony of sounds echo around the forests from crickets and frogs.  Immediately after a shot, all of these creatures very briefly go silent – they know that something has happened! And then they ramp up again.  We also see other animals prowling around, including amardillos. A meteor shower occurred during our final night of blasting, which we could see quite well from the rural stretches of Georgia, far from light pollution of population centers.

Jim Gaherty illuminates a steaming hole that formed over the shot site from the blast.
The shot team filled in this hole the next day.Armadillo patrols one of shot sites.

More updates from our field teams...

Sun, 08/09/2015 - 12:35

Seventeen teams are rounding up 1953 small seismic stations along our 350-mile-long line across eastern Georgia, and they continue to send texts and pictures with updates on their work…

“21757. Still kickin”
Kevin hunts for missing texans with the metal detector....
“Team 11 is all done and headed home to the mother ship”

“We’re not coming back unless we have all of them!”

“We had a helper at site 20431!”

“Hello Donna Rach and I are crushing it right now”

“Daily check in, we’re making good time so we should see the puppies soon enough”

Making metadata...
“Recovered a Texan at stop 20858. This one doesn’t seem to be working correctly, whenever I press it it just tells me things like “The Cowboys are America’s team” and “Bush was an American hero”. Weird.

“We got to 20170 the one with the ant colony”

Loaded up with Texans and geophones
“Stop 20804. Everything’s fine, except some guy came out of the woods and bit Brent. All he’s saying now is “brains” and is acting super creepy. I’ll keep an eye on it and only use the shovel if necessary”

“Will do! I will let you know if we become stuck… Looks likely”

Unearthing another Texan

“Just beat the downpour and headed for base”

“Stop 20879. Found the Texan disconnected from the geophone on top of where we buried it with pieces of bag around it, looked everywhere for the geophone. Found it about 5 m down the hill near the tree line with bite marks all along it. Either an animal dug it up or a very hungry confused thief”

Picking up litter?
“Found 2 dollars at 21058! Who says geology doesn’t pay well?”

Was not seen on the line...
Was seen on the line... yikes.

Best texts from the field (so far...)

Thu, 08/06/2015 - 07:43
Seventeen teams have been out deploying small seismographs and geophones along a 300-mile-long profile across eastern Georgia, and they have been checking in with me regularly by text message. Some highlights from texts and pictures from our groups:

“Team4 is Done! I repeat again, 4 is done! Heading back to the sweet onion city! ☺”

“Still alive”

“Team gruesome twosome on our way back to the hub”

“We are gonna skip installing 21520 because both sides of the streets are well maintained yards and there’s not a great place to put a Texan”

“We’re done! Just kidding haha. We’re on our second!”

“We’re in the zone”

“All geophones buried --- I am beat. Where’s a can of spinach when ya need one, lol”

“It's a long way to the top if you want to study rocks”
"Sunrise at station 21779"
“We’re dirty but doing well!”

“Still digging. Still have not reached China. Will attempt again on next hole”

“On 20186 and we lost our bubble level. We even dug up the last geophone to see if I accidentally buried it”

“We just deployed our last station, 20224. Can we go to Jekyll Island?”

Donna Shillington, LDEO

Digging Holes and Filling Batteries -- A party in Vidalia, Georgia

Tue, 08/04/2015 - 07:52

The SUGAR deployment team arrived en-masse on Saturday bringing the Line 2 personnel total to a whopping 45! The day started off with science and overview lectures by the SUGAR principle investigators Donna Shillington and Dan Lizarralde.  Students diligently rearranged the ten’s of Texan boxes into a makeshift lecture hall, complete with a projector and a Bluetooth sound system. 

With the science lecture complete and stomachs full of pizza, the entire group ventured out to conduct a practice deployment under the watchful eyes of the PASSCAL instrument team.  All 17 teams participated in the activity, standing in a single file line in front of our hotel digging practice holes, connecting the Texans to the geophones, and mindfully orientating them with their handy-dandy bubble levels. 

After a sweat filled hour under the Georgia sun, we caravanned back to the instrument center for a “battery party”. I call it a battery party in honor of the “streamer parties” that students will often participate in on active source seismic research cruises in which kilometers of cable need to be reeled off and rearranged.  In our case a battery party consisted of the 32 students placing 2 D-cell batteries inside each of the 2,000 Texans.  The instrument center quickly transformed from an orderly lecture hall into a mass of empty battery boxes and disassembled Texans though despite the apparent chaos, we got the job complete and the Texans filled in only a few short hours. 

Next up will be flagging the instrument locations and the actual deployment.  We have our fingers and toes crossed for dry weather and safe road conditions as the student teams prepare to set off on their flagging and deployment expeditions. 

Natalie Accardo - Columbia University, LDEO

The SUGAR2 deployment team hails from all across the United States
covering more than 15 states and 21 different universities/institutions.   

The deployment team sits with rapt attention listening to
the science and overview lecture.

Students practice digging holes and deploying Texans
near our hotel in Vidalia, Georgia.
Students and PASSCAL personnel take over the instrument center
filling 2,000 Texans with D-cell batteries.
The "battery party" comes to an end as the last Texans are filled and
the boxes are rearranged for easy late-night programming by the PASSCAL team.  

2000 “Texans” with all the fixin’s….

Sun, 08/02/2015 - 09:21
During our project, we plan to record sound waves generated by a series of controlled blasts on two profiles, one with 2000 instruments (“Texans”) deployed along a 350-mile-long profile across Georgia and another with 700 Texans deployed along an 80-mile-long profile.  In total, that’s 2000 instruments and 2700 deployments!! Lot of instruments means lots of stuff.   The basic components of the instruments themselves were shipped in ~160 big plastic boxes arranged into ~18 pallets.  Each of these instruments will be powered by two D-cell batteries. To power the instruments for both lines, we needed 5500 D-cell batteries.  We picked them up from the Lowes in Vidalia as a 2000-lb pallet.  For each station, we also need flags to mark the locations, and bags and tape to protect the data recorder.  We very quickly filled up our 1800-square-foot field center in Lyons, GA with all these goodies…

Donna Shillington,  LDEO

Freshly delivered pallets of boxes holding all the science equipment
The PASSCAL team re-arranged the boxes into a T for their own devious reasons :)The trusty Silverado loaded down with 2000 pounds of batteries! (Dan for scale).

Drill, Baby Drill! Drilling and filling for the SUGAR seismic shots

Fri, 07/31/2015 - 12:14
We are using sound waves to image the subsurface of Georgia along two long transects.  It is like creating a huge x-ray of the geology in the region. Thousands of instruments (termed “Texans”) will record sound waves that are generated from a series of controlled seismic sources (“shots”) that we will set off along the line. 

For the last few weeks, the seismic source team, based at the University of Texas – El Paso, and the drillers have been hard at work drilling twenty-six 60- to 100-foot-deep holes that will contain the explosives used to create the sound waves.  Once the holes are drilled (the first stage of which is termed spudding), emulsion explosives with boosters and caps are carefully installed in the base of the hole and the remaining height is filled in with dirt and gravel (“stemming”). 

Now with the 26 shots drilled and patiently waiting for the electronic signal to blow, all we have left to do is deploy the 2,000 instruments that will record the sound waves … An easy feat for the 50+ scientists, students, and engineers descending on Vidalia, GA over the next few days.  Stay tuned for our progress and adventures as we continue on this epic scientific undertaking.

Natalie Accardo - LDEO

The SUGAR seismic source and science team from left to right:
Steve Harder, Dan Lizarralde, Ashley Nauer, and Galen Kaip
The drill rig set up and drilling a shot on SUGAR Line 2.

Galen Kaip prepares the source charges (white tubes) on the truck bed as
the drillers complete a shot hole.
The source team carefully lowers the prepared seismic charges into the complete shot hole.
Ashley Nauer (red hat) stands waiting with shovel in hand to fill the remaining height of
the hole with sand and gravel.   
The drill team monitors the process of spudding, the very first stage of drilling the
shot hole, for SUGAR line 2.
The source team and drill team push on late into the night to ensure the completion of the
final shot for the entire SUGAR experiment.  

Ramping up for bigger, badder SUGAR Part 2

Tue, 07/28/2015 - 23:11
We are in Georgia gearing up for the second phase of field work for the SUGAR project, which will involve collecting seismic refraction data along two profiles spanning eastern Georgia. In the coming weeks, we’ll deploy thousands of small seismometers along county and state roads across the region, which will record sound waves generated by a series of controlled blasts. We can use the sound waves to make pictures of geology beneath the surface. Geological structures beneath Georgia record the most profound events involved in the formation and evolution of the eastern North America continent. In particular, we want to image an ancient suture between Africa and North America that formed when these continents collided to create the supercontinent Pangea, frozen magma bodies from one of the biggest volcanic outpourings in Earth’s history, and continental stretching and thinning that lead to the breakup of Pangea and formation of the Atlantic Ocean.

We collected similar data in western Georgia last year during the first phase of the SUGAR experiment imaging these same features. During that field program, we deployed 1200 seismometers and set off 11 controlled blasts along a 250-mile-long line, which felt like a big project at the time. But this year, we will go even bigger! In eastern Georgia, we need to span an even larger area to encompass our geological targets. One of the reasons that we need to look at a bigger swath of the earth is that there is a debate about the location of the suture here – it could be as far north as Milledgeville, GA or as far south as Baxley, GA. (In case you are not up on your Georgia geography, those towns are ~100 miles apart). This means longer profiles, more instruments and more blasts! We will deploy a total of 3000 seismometers and detonate 25 blasts along two profiles. The longer profile spans 350 miles from Winder, GA to the Florida-Georgia state line near St Mary’s Georgia. Stay tuned!

Donna Shillington, LDEO

Stay Tuned for SUGAR 2!!

Wed, 07/22/2015 - 21:57
In just a few short weeks a mass of students and scientists will descend on southern Georgia with work boots and sunscreen in hand to take part in the second portion of the SUGAR active source experiment.  Make sure to stay tuned for regular updates on our progress and to learn more about the exciting science that motivates this amazing field expedition!

Long lines and lots of instruments

Tue, 03/25/2014 - 11:38
If you want to image the Earth’s crust and upper mantle with seismic data, you need to record the arrival of seismic waves that have propagated down to, in our case, depths of up to ~30 km.  These deep-diving phases travel quickly through the denser, higher velocity rocks of the lower crust and upper mantle, and they arrive back at the surface ahead of shallower phases at long source-receiver offsets (see video below).  

To record these lower-crustal and upper-mantle phases as “first arrivals”, where they are not obscured by the arrival of energy from shallow paths, we use long lines.  Long lines mean lots of receivers and lots of driving to deploy and recover these instruments.  We could have used lots of sources instead, but the blasts we used to get seismic energy into the lower crust and upper mantle in this experiment take a lot of time and money to setup.  Receivers are much cheaper, so we used a lot of them.  (For similar wide-angle/long-offset work at sea, airgun sources are cheaper than putting seismometers on the seafloor, so we use many shots and a smaller number of receivers out there.)

This time-lapse video shows Team 13 of 14 recovering 89 of the 1200 total short-period seismograph stations from where our line crossed Fort Benning, near the northwestern end of the line.

Nathan Miller, LDEO

Deploy in the rain, recover in the sunshine…

Tue, 03/25/2014 - 00:32

Weather map during deployment.
When the time came to install our 1200 small seismographs across Georgia at the flagged positions, the rains came….   A lot of rain.  During our first deployment day, we received 1-2 inches of rain, and another wave of rain clouds came through on Day 2 (check out map). Roads that used to be easily passable became mudholes or were flooded with water. All-wheel-drive vehicles and drill rigs alike got stuck, and a few station locations could only be reached on foot. Our hard-working field crew labored in the rain digging holes and deploying seismometers.  Vehicles, equipment and people were covered in the famous Georgia red clay (and other muds and sands of Georgia and northernmost Florida). Adding insult to injury, problems with the programming of some of the instruments meant that we actually had to pick up and redeploy many of them. It was a mudbath.  Nonetheless, our field crew managed to deploy 1200 seismometers across Georgia by Tuesday at sundown. It was an impressive show of endurance, and an inspiring display of positivity given the number of people that were still smiling and upbeat at the end of it all. 
A couple of days later, after our seismic shots, it was already time to pick up the instruments, and the weather changed completely.  The sun shined on SW Georgia, and we picked up almost every last seismometer in just one day under blue skies….  
Donna Shillington, LDEO

Video of shots L1-05, 06, 07 and 08

Sat, 03/22/2014 - 22:52
Shooting a land refraction experiment is more difficult in almost every way than collecting a comparable dataset at sea.  Far more difficult.  But I can't think of anything at sea that compares to the experience of setting off a series of shots at night.  On the first night of shooting, Steve, Nathan, Meghan and I detonated shots L1-05, 06, 07 and 08, while Galen, Donna and Natalie shot 14, 13, 11, and 10, and Tina, Adrian, James and Semir shot L1-04.  I recorded the video clips linked below at our shots (05-08).

To someone who hasn't seen a seismic source shot before, there really isn't a good way to describe what a good shot feels like, except as something you haven't felt before.  We had a number of students watching L1-05 being shot, since this location is quite close to Americus.  The video of L1-05 is completely lacking in drama, which is a good thing; but that shot gave us all a great ride.  The 100 pounders 06 and 07 were also surprisingly good.

We made gathers for most of the shots today. The dataset is fantastic, and 05, 06 and 07 produced super record sections.  L1-08 committed most if its energy to the air, but it shook the ground nicely and I've got a feeling those data are going to be great too.

The video is here:


Random Pictures from the Road (and otherwise)

Wed, 03/19/2014 - 13:43
As a follow follow up to Chastity's post, I thought a few random pictures from the road would be entertaining. I have been part of group 5 and as such responsible for the part of the line that spans from Hahira in the south to just north of Adel.

 South-central part of the seismic line. The yellow line is team 5's section.  We have been in a relatively rural part of Georgia and as a result have not encountered many locals save a few who have stopped to ask if we are ok. However, we have seen quite a few interesting things that are quite out of the ordinary (to me at least).

Friendly Muscovy duck.Rocks in a stream bed with associated pink spongy material (?)
Spanish moss.Linguoid (current) ripples on a washed out road. We have also seen quite a few old abandoned farm houses in various stages of aging...

At least 10-15 dogs were standing guard at this house, including about 8 puppies.

Caroline making some new friends.
All said we have dug 122 holes in team 5's stretch. We have also helped deploy instruments in other sections as well and while doing so have seen others hard at work.

Meghan and Nate getting it done!Along the way the cars have taken quite a beating and have actually held up pretty well. Although there have been a few instances where people got stuck, I think that the people with the toughest job will be the guys that have to detail the cars upon their return...

A more appropriate vehicle (?)And lastly here's a couple more random pictures that I thought were interesting.

The large disparity in fuel grade gas prices.
A ~perfectly leveled geophone (it's harder than you'd think).Hopefully this random selection of pictures was entertaining. Up next we will post about last night's "shots." In the meantime, I can say that they were all successful with varying degrees of excitement. The most important thing is that all of our hard work is being realized as the instruments are recording refractions from buried geology that will help us unravel some of the mystery that surrounds events that happened in this area long ago.

James Gibson, LDEO

Rain, geophones, and animals … Oh my!

Tue, 03/18/2014 - 17:15

Chastity Aiken
Georgia Institute of Technology

Flags, Flags, and More Flags - Locating the sites for 1200 instruments

Sat, 03/15/2014 - 23:14
Many of the SUGAR field team arrived in Americus, GA on Wednesday to start helping with the massive charge of deploying 1200 seismic instruments along the SUGAR seismic line.  The seismic line spans 200 miles from northwest Georgia to just past the Georgia-Florida border; a 4+ hour car drive from end to end!  Everyone gathered early Thursday morning on the idyllic Georgia Southwestern State campus to meet with the chief scientists and learn about the proper techniques for identifying installation sites for the seismographs (just the first step in installing the instruments).  With neon orange safety jackets, numerous maps, GPS devices, packets of official permitting documents, and heads full of safety precautions the field team split into seven two-person pairs each equipped with their own squeaky clean rental car (though they didn’t stay clean for very long!).  
The fleet of SUGAR rental cars looking clean and shiny before being driven
into the field where they undoubtedly got a little mud on their tires.
Each pair of field assistants was given a segment of the seismic line to drive and flag locations for instrument installation deemed safe both from the seismograph (i.e. dry, firm soil) and the install team (i.e. a safe distance from the road).  Given the shear distance of the seismic line, teams found themselves amid diverse backdrops from rolling farmland with overly friendly cows to buzzing residential neighborhoods to sandy stretches flanked by towering groves of Ponderosa Pine trees. 
Antonio placing a flag and using a GPS device to note the location where a
seismograph will be installed amid the sandy surroundings of a Ponderosa Pine farm.
Every team was able to flag all their sites within just two days leaving us the luxury of a sunny Saturday morning free for exploring more of our beautiful Georgia surroundings.  Next up is the actual task of installing the 1200 seismographs which will involve twice the people, six more (temporarily clean) vehicles, and of course countless exciting adventures from the field.  Happy (almost) St. Patrick’s Day from Americus!
A picturesque county road near Jasper, FL along which instruments will be deployed.
-- Natalie Accardo, LDEO

A day with the seismic source team in photos

Fri, 03/14/2014 - 23:43
The source of sound waves for the SUGAR experiment will be a series of controlled blasts along the profile.  For each of these, we drill a 60-100 ft deep hole, place emulsion explosives with boosters and caps at the base of the hole, and fill in the rest of the hole with dirt and gravel.  Each seismic source location requires a substantial amount of work by drillers and the UTEP seismic source team.  Below, Adrian Gutierrez shows a day in the life of the source team with pictures (Donna Shillington, 13 March 2014)

Adrian Gutierrez, 13 March 14
7:30 am: Leave Georgia Southwestern State University, where we are staying, and head to the site8:20 am: Arrive at site 8:30 am: Start drilling and take geological samples every 5 ft.

9:00 am: Dyno Nobel truck arrives; load emulsion into cut PVC pipe sections that serve as a holders for emulsion.
9:30 am: Surprise visit from other scientists on the project9.50 am: Setting up the booster in the emulsion.11.20 am: Loading the explosives into the drill hole12.00 pm: Drill crew starts removing their equipment12.45 pm: Tagging the charges and plugging the hole3.15 pm: Move onto the next drill site.Nighttime: Finally back to the dorm.

Arrival of the seismic equipment!

Tue, 03/11/2014 - 19:57
Boxes with seismographs and other equipment
During this project, we will deploy 1200 small seismographs along a 200-mile-long (300-km-long) profile across Georgia.  All of these seismographs were shipped to Georgia from Socorro, New Mexico. This is the headquarters of the Incorporated Research Institutions for Seismology (IRIS) Program for Array Seismic Studies of the Continental Lithosphere (PASSCAL), a facility that provides seismic instrumentation to US researchers.  It takes a lot of boxes to hold all 1200 seismographs and the associated equipment and tools.  There are 15 seismographs per box, so that's 80 boxes alone without counting boxes for geophones, etc. 

Fortunately, we have a lot of space! Our field headquarters is located in a historic gym on the campus of Georgia Southwestern State University in Americus, GA.  Faculty and staff at GSW have been extraordinarily generous with their time and expertise. They are allowing us to use the Florrie Chappel gym as our base of operations, and they have helped us enormously with Georgia geology and logistics coordination, handling our huge shipment of equipment and supplies, housing on the campus (many of us are staying in one of the dorms!), setting up the gym with internet access, power, and tables, and much, much more. Today, they moved all of the boxes with our seismic equipment from the shipping warehouse to our field headquarters in the gym. I can sense that all of our seismic instruments are itching to be deployed....
Pallets waiting outside the Florrie Chappell gym
Donna Shillington
11 March 2014

More preparations: mini seismic experiments

Mon, 03/10/2014 - 11:31
A geophone in grass, awaiting sound waves.

To prepare for our big seismic experiment, we have collected a couple of miniature seismic datasets.  The shallow geology varies substantially along our profile and is very important for planning the depth of drilling and size of our seismic sources. In particular, we need to determine the depth to a limestone layer in a few places.   The same seismic method that we will use to understand the deep geological structures beneath Georgia can also be used at a smaller scale to examine layering in the upper ~100 ft (~30 m) beneath the surface. We recorded the data on 24 geophones attached to a 230-ft-long (70-m-long) cable.  The source was a modified shot gun that looks like a pogo stick.  We drilled small holes in the ground, loaded the gun and stuck it in the hole. To limit the kickback, we weighted the gun down with a metal plate topped by two heavy jugs filled with sand. Hit the plate with a mallet and – BANG – a seismic source! Not a bad way to spend a sunny Sunday!

Check out Dan firing the seismic source...

Donna Shillington
9 March 14