Man-made sinkholes

This is recirculating again on Facebook because of a web admin trick to increase "likes" and therefore advertising on their pages ("Press Like and type 1 to see what happens next"; nothing happens except the Like).

Previous sinkholes in Guatemala were due to ruptured sewer lines.  It reminds me of a friend in Penn Hills Township outside of Pittsburgh.  In seeking finance to buy a house, the would-be lender discover the septic/sewage line to most of the homes in the neighborhood were open directly to an abandoned mine shaft with no treatment.  You can imagine the groundwater problems that causes, as well as other dangers.

JAE

Sinkhole in Guatemala

2010 sinkhole spurred by tropical storm Agatha.

A roughly 30-story-deep sinkhole in Guatemala City. (More photos)

Photograph courtesy Paulo Raquec

Ker Than

for National Geographic News

Published June 1, 2010

A huge sinkhole in Guatemala City (map), Guatemala, crashed into being on Sunday, reportedly swallowing a three-story building—and echoing a similar, 2007 sinkhole in Guatemala.

The sinkhole has likely been weeks or even years in the making—floodwaters from tropical storm Agatha caused the sinkhole to finally collapse, scientists say.

The sinkhole appears to be about 60 feet (18 meters) wide and about 30 stories deep, said James Currens, a hydrogeologist at the University of Kentucky.

(See more photos of the Guatemala City sinkhole, and a Texas sinkhole picture.)

Sinkholes are natural depressions that can form when water-saturated soil and other particles become too heavy and cause the roofs of existing voids in the soil to collapse.

Another way sinkholes can form is if water enlarges a natural fracture in a limestone bedrock layer. As the crack gets bigger, the topsoil gently slumps, eventually leaving behind a sinkhole.

It's unclear which mechanism is behind the 2010 Guatemala sinkhole, but in either case the final collapse can be sudden, Currens said.

(Related: "Sinkhole Holds 12,000-Year-Old Clues to Early Americans.")

2010 Guatemala Sinkhole Could Grow

A ruptured sewer line is thought to have caused the sinkhole that appeared in Guatemala City in 2007.

The 2010 Guatemala sinkhole could have formed in a similar fashion, Currens said. A burst sanitary or storm sewer may have been slowly saturating the surrounding soil for a long time before tropical storm Agatha added to the inundation.

"The tropical storm came along and would have dumped even more water in there, and that could have been the final trigger that precipitated the collapse," Currens said.

(See Guatemala pictures from National Geographic Traveler magazine.)

Depending on the makeup of the subsurface layer, the Guatemala sinkhole "could eventually enlarge and take in more buildings," he said.

Typically, officials fill in sinkholes with large rocks and other debris. But the 2010 Guatemala sinkhole "is so huge that it's going to take a lot of fill material to fill it," Currens said.

"I don't know what they're going to do."

More: Traveler's overview of recent Guatemala natural disasters >>

Watershed Job Opportunities

1.) Jug Bay Wetlands Sanctuary, Director – Closing date December 31, 2012

2.) Chesapeake Bay Program, Communications Office Staffer -- Closing date: January 7, 2013

3.) Wetland Studies and Solutions, Inc., Entry-level engineers and/or landscape architects – Closing date: January 14, 2013

4.) Trout Unlimited (TU), Habitat Project Coordinator – Closing date: January 14, 2013

5.) Executive Director, StreamWatch – Closing date: January 15, 2013

6.) James River Association, Field Educator – Closing date: January 18, 2013

7.) Healthy Watersheds Internship, EPA Water 2012-253

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1.) Jug Bay Wetlands Sanctuary, Director – Closing date December 31, 2012 – The Sanctuary Director is responsible for overseeing Sanctuary operations and programs, and for staff supervision. The Sanctuary Director implements the core mission of the Sanctuary consisting of environmental education, ecological research and environmental stewardship programs. BS required, MS or higher preferred. To view the position description or apply, visit: http://agency.governmentjobs.com/annearundel/job_bulletin.cfm?JobID=567127. For more information, contact Debra Gage at rpgage00@aacounty.org.

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2.) Chesapeake Bay Program, Communications Office Staffer -- Closing date: January 7, 2013 – Activities include providing information to the public, working with the media, branding and promoting the Chesapeake Bay Program, and facilitating communications between state and federal agencies. Special emphasis is placed on using multimedia content and online tools in the office's daily work.  Job posting available at http://www.chesapeakebay.net/jobs. 

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3.) Wetland Studies and Solutions, Inc., Entry-level engineers and/or landscape architects – Closing date: January 14, 2013 -- Projects include stream restoration, low impact development, urban stormwater management design, wetlands mitigation design, and floodplain studies. Ideal candidate will have from 0 to 5 years of experience, EIT (if applicable), and knowledge of AutoCAD, AutoCAD Civil 3D, SWMM, HEC-HMS, HEC-RAS, TR-55, and Microsoft Office.  Submit resume, cover letter, salary requirements, and list of professional references (no calls) to: Wetland Studies and Solutions, Inc., Attn: Kate Tomlinson, 5300 Wellington Branch Drive, Suite 100, Gainesville, Virginia  20155, Fax: (703) 679-5601; E-mail: ktomlinson@wetlandstudies.com.  For more information, see www.wetlandstudies.com (Careers). 

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4.) Trout Unlimited (TU), Habitat Project Coordinator – Closing date: January 14, 2013 -- Full-time position in northcentral Pennsylvania – Will inventory stream crossings (i.e. road culverts), coordinate fish habitat improvement projects, and conduct pre- and post-construction monitoring.  Send cover letter, resume, and 1-2 page writing sample to:  Habitat Project Coordinator Position, Trout Unlimited, 18 East Main Street, Suite 3, Lock Haven, PA  17745, awolfe@tu.org.  No phone calls – TU staff will contact qualified applicants in January, 2013.  For more information, see http://www.tu.org/about-us/jobs

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5.) Executive Director, StreamWatch – Closing date: January 15, 2013 -- Location: Charlottesville, VA -- Full/Part Time: Full time 35 hours/week;  Regular/Temporary: Regular exempt position; Reports to: Board of Directors -- StreamWatch is a non-profit organization located in Charlottesville, VA, dedicated to monitoring and reporting the health of the Rivanna River watershed’s streams. The Executive Director is responsible for overall leadership and implementation of StreamWatch’s mission.  Applications should be submitted by email to admin@streamwatch.org.  More information is available at http://streamwatch.org/jobs.

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6.) James River Association, Field Educator – Closing date: January 18, 2013 -- Full-time, seasonal 10-month position starting February 2013 -- During March to June and September to November, the Field Educator will assist with weekday school-group programs, and weekend overnight camping excursions with extracurricular youth groups.  Additionally, the field educator will help lead canoe-based river expeditions during the summer, offsite paddle programs, and educational events as needed. To apply, mail or email resume and cover letter to Jessica Templeton, James River Association, 9 South 12th Street, 4th Floor, Richmond, VA 23219; Email:  jtempleton@jrava.org.  For more information, see  http://www.jamesriverassociation.org/about-jra/employment

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7.) Healthy Watersheds Internship, EPA Water 2012-253 -- Location: Washington, D.C.; Type of Position: Full-time, renewable annually for up to 3 years; Salary: Negotiable -- A postgraduate internship is available at the U.S. Environmental Protection Agency’s (EPA) Office of Water. The participant will have the opportunity to learn about EPA's Healthy Watersheds Initiative. The participant will be involved in healthy watersheds assessments, help develop coordinated protection programs, and identify opportunities to integrate healthy watersheds protection into EPA programs. A detailed description of this position can be found at the Oak Ridge Institute for Science and Education's web site: http://orise.orau.gov/science-education/internships-scholarships-fellowships/description.aspx?JobId=12574. This job announcement can also be found at chesapeakenetwork.org in the Job Announcements folder of the Community Resources Section. Applicants must have received either a master’s or a doctoral degree in aquatic ecology, environmental science, or biology within four years of the desired starting date, or completion of all requirements for the degree should be expected prior to the starting date.

Wrapping up the semester

Thanks to everyone for pulling your projects together over the last week.  For those who haven't finished, please remember to share a proposed workplan with me over the weekend.  You may take up until the end of the Winter Break to finish things, unless you're one of the folks who are evolving a specific project into a much larger-scaled outcome (capstone).

Over the weekend I'll begin assembling your products into larger collections to share with future students, but you'll be able to continue updating them as desired.

At any time, even years from now, don't hesitate to ask for help accessing something you've submitted or the Projects pages I created for each of you.

It seems weird to say I'm proud of your work, because in this course it really is all YOUR work; so instead know that I'm proud to know and be associated with you and your work!

Urban Wildlife - Hawk and Squirrels

While working at my laptop on Sunday I had the good fortune to notice this Sharp-shinned Hawk (Accipiter striatus) probably a juvenile female - fly into the large Sweetgum tree (Liquidambar styraciflua) in my neighbor's back yard.

I was taking photos with my old phone, frustrated there were no windows without a screen, when two nervous but curious, juvenile Grey squirrels  (Sciurus carolinensis) appeared.


Although blurred by the screen, the interaction is interesting to watch.  The juvenile squirrel is much larger than the small hawk's normal prey, but it's surprising the hawk doesn't lose its patience.  This ends well - safe for kids to watch.

The video:

VT Student Feedback on Teaching

I just received this. You may have already received something similar and replied.  If so, thanks! Laughlin, Anne <laughlin@vt.edu>
to OFFICE_OF_ASSE.

Dear Colleagues,

It is mid-point in the two week period when students can submit feedback through the online Student Perceptions of Teaching (SPOT) system. Currently, responses are coming in more slowly than they have in past semesters. While the university-wide response is about 70% each term, some instructors have taken steps to achieve online response rates of 80% or better. Instructors who receive high response rates tend to do the following:

Communicate with Students about SPOT

·         Direct all students to the login page ( eval.scholar.vt.edu ). After login, they will see a link to the SPOT survey for each of their classes.
·         Share examples of how you have modified class content or instruction based on past student feedback. 
·         Teach students what it means to provide constructive feedback (e.g., keep comments narrowly focused and include suggestions for improvement).
·         Impress upon students that practicing constructive feedback is part of professional development – it is a learned skill that will show its value long after graduation.

Provide Class Time for SPOT

·         Ask students to bring their laptops to class and offer 10 minutes for them to complete the SPOT survey.

Assure Confidentiality

·         No identifying information is associated with responses when they are shared with instructors. Knowing this may help students to be more comfortable with responding.

DC takes steps to clean waterways

From the Washington Post:

D.C. debates best path to cleaner waterways

(Linda Davidson/ The Washington post ) - Trash and debris collect along the shores of the Anacostia River near Nationals Stadium in Washington, D.C.

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By Darryl Fears, Published: December 2

For environmental activists who fight to clean the District’s dirty waterways, there was no sweeter victory than the one they witnessed in 2004.

That year, the D.C. Water and Sewer Authority was forced to settle a federal lawsuit that claimed it failed for decades to stop its Civil War-vintage sewers from spewing pollution. D.C. Water agreed to build three huge tunnels within 20 years to stop pipes from overflowing during hard rains, sending billions of gallons of storm water mixed with raw sewage into Rock Creek and the Potomac and Anacostia rivers every year.

“Maybe . . . before I pass away, I can see children swimming in there,” Robert Boone, the former president of the Anacostia Watershed Society, said shortly after the settlement was reached.

But now, the three-tunnel solution is in doubt, and activists, engineers and bureaucrats are arguing once again about the best path to cleaner waters. Although digging is underway for the first tunnel, D.C. Water wants to put the other two on hold and instead see whether rain gardens, retention ponds and grass rooftops can soak up as much storm-water runoff as the pipes can store.

D.C. Water has asked the Environmental Protection Agency for permission to build an experimental “green infrastructure” project and run tests for at least eight years.

The green project would be built where the second and third tunnels were slated to run, along Rock Creek Parkway near the Kennedy Center to protect the Potomac River and in Upper Northwest neighborhoods to protect Rock Creek. A 13-mile tunnel under the Anacostia River and deep into the Northeast near a Home Depot off Rhode Island Avenue, currently under construction, would continue as planned.

The EPA is considering D.C. Water’s proposed “partnership agreement,” and a decision on whether to move forward with public hearings on the changes is expected soon.

Among local environmental activist groups, a verdict on the request is already clear: Don’t do it. Some are enraged; others have expressed dismay about the proposal.

“We’re well down the road to the tunnel solution, and I’m a little ambivalent about changing course midstream,” said Brent Bolin, a spokesman for the Anacostia Watershed Society.

Opponents say that if the green pilot project wins approval, billions of gallons of sewage would pour into the Potomac and Rock Creek for eight years while D.C. Water conducts its tests.

The proposed agreement played a major role in the recent firing of the head of the D.C. Department of the Environment (DDOE), Christophe Tulou. He said he believed the green infrastructure project had no hope of performing as well as the utility claimed, and he allowed experts in his department to say as much in comments on the project submitted to the EPA.

In a recent interview at his home, Tulou, now unemployed, said his department “had no beef about green infrastructure. But there are still issues one has to resolve . . . how effective is green infrastructure in mitigating storm-water runoff. We don’t know exactly.”

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