Subscribe to our free daily newsletters
. Earth Science News .

Subscribe to our free daily newsletters

Sediment research is a granular exercise at NRL
by Staff Writers
Stennis Space Center MS (SPX) Aug 21, 2017

Researchers (from left) Dr. Blake Landry, Ed Braithwaite and Dr. Joe Calantoni mount a battery bottle on one of NRL's quadpods in preparation for a field deployment off the coast of Virginia. The batteries provide power to the various instruments mounted on the quadpod that measure waves, currents and the seafloor while deployed on the ocean bottom. (Photo by Michael R. Hart)

It's an unseasonably warm February afternoon at the U.S. Naval Research Laboratory, Stennis Space Center (SSC), Mississippi, where three men are tinkering with a 7-foot tall, four-legged instrument platform, preparing it for an upcoming research experiment off the coast of Virginia.

The rugged apparatus known as a "quadpod," was built to withstand being on the bottom of the ocean for weeks at a time, measuring waves, currents, and seafloor change.

"It's equipped with imaging sonar to capture the motion and burial of munitions on the seafloor," said Joseph Calantoni, head of NRL's Sediment Dynamics Section at SSC.

Calantoni, a research physicist, leads a team of 12 scientists and engineers. Their mission is to make predictions of the subaqueous environment for the Navy, "and exploit these predictions to improve underwater acoustic communications, improve our ability to find buried objects and the Navy's capacity to put troops on the beach.

"We spend a significant amount of time determining what conditions can move unexploded ordnances (UXOs) around the seafloor. That's where the quadpod comes in," he said.

To accomplish their munitions research, Calantoni and his team fabricate replica UXOs with the same shape, size, and density of real ordnances found unexploded on the seafloor.

"The focus of this research is to understand how the waves and currents either transfer or bury these unexploded bombs," Calantoni said.

Understanding how Mother Nature's fluctuating weather conditions affect underwater munitions is an important focus of NRL's sediment research, but the team's primary mission is to quantify how the sediment on the seafloor, river bed and estuaries around the world is affected by the forces of nature - hurricanes, typhoons and heavy storms, or even the daily ebb and flow of tides, waves and currents.

"We are focused on sediment properties as they apply to problems of interest for the Navy," Calantoni said. "One of the Navy's many missions is to put Marines and special forces on the beach."

Calantoni emphasized why it's critical to understand how the beach behaves during a storm.

"Clearing sea lanes to bring troops from ship to shore is of great importance to the Navy's mission, but that process requires a lot of instrumentation and personnel," he said.

"We provide the R and D (research and development) to help operators make informed, tactical decisions."

According to Calantoni, mine warfare is and has been a significant concern of the Navy for centuries, to ensure safe sea lanes and at-sea operations.

"You can go all the way back to World War II during the Normandy Invasion, where there were problems with transports getting stuck on sand bars," Calantoni said. "Understanding how storms, waves and currents affect sand bars, for example, is still a challenge for the Navy."

His section's research illustrates how satellites provide useful images of waterways, rivers and other bodies of water, but sometimes the images can be unclear and few days old.

"Can we tell how those sand bars have changed in those few days? That's a big focus of our work," said Calantoni.

The group's research also involves modeling and simulating potential and current naval operating areas, with models ranging from grains of sand up to kilometers of coastline.

"This simulation is useful in predicting how a sand bar on a beach might change during the course of a Nor'easter off the coast of North Carolina, for example," Calantoni said.

"The Navy's ability to communicate under water is strongly dependent on the shape of the sea floor," he continued. "Being able to predict the roughness of the sea floor - the presence of ripples or not - is very valuable for the Navy to conduct operations."

Those operations are also dependent on the research conducted in the field, where highly sensitive instruments are used in the ocean, rivers and estuaries.

"We make a lot of predictions using remote sensing techniques," said Calantoni.

According to Meg Palmsten, an oceanographer in NRL Stennis' Sediment Dynamics Section, remote sensing, using video cameras attached to unmanned aircrafts, towers, or even other researchers, is used to observe and study waves and currents moving toward the shore.

"Our work is important because waves and currents move the sediment around on the ocean floor, which can create navigation hazards" said Palmsten. "We conduct our research all around the world in many different environments. The goal is to have the data we collect incorporated into a tactical decision aid."

Tactical decision aids help the warfighter make informed decisions given the best available data. Combining the lab work, along with numerical and field observations together is a key element in providing the warfighter information about their environment.

Allison Penko, a coastal engineer also on Calantoni's team, and an expert in analyzing the movement of sand in the ocean, uses laboratory equipment to study small-scale processes occurring on the seafloor. The Small-Oscillatory Flow Tunnel (S-OFT) at NRL simulates the forcing on the seafloor from waves and currents. The rectangular, acrylic tunnel has several instruments to measure the flow over a sand bed at high-resolution.

Penko spends much of her time developing numerical models and laboratory experiments to study a large range of flow conditions causing turbulent interactions on the seafloor.

"We're using the information collected in the laboratory, field, and from models to examine processes on the sea bed to learn how those processes affect large-scale sand movement."

Remote sensing also plays a key role in Penko's work.

"They Navy is interested in operational time frames, so we focus on forecasting up to four days," Penko said. "Remote sensing helps to make our predictions more accurate by incorporating those observations into our models."

Penko expressed the importance of providing accurate information to the warfighter. "If we have to send Marines up a river and then a storm occurs, we need to be able to tell them if it's safe to navigate back."

Calantoni and his team are fully aware of the complexity of their research and how a team effort is a driving force toward success.

"We have physicists, oceanographers and all sorts of engineers - civil, ocean, mechanical, electrical and technical - as well as computer scientists who are very important to the work we do," said Calantoni. "This is the fun part, merging multiple disciplines and working on challenging problems.

"If it's not a hard problem, then we shouldn't be working on it here at the U.S. Naval Research Laboratory."

Navy issues environmental exemption for towed sonar array
Washington (UPI) Aug 15, 2017
The U.S. Navy has issued a National Defense Exemption under the Marine Mammal Protection Act to continue testing and operating its Surveillance Towed Array Sensor System Low Frequency Active Low Frequency Active towed-sonar array. The move would extend the exemption for another two years or until final rules are issued by the National Marine Fisheries Service on mitigating possible harm ... read more

Related Links
Naval Research Laboratory
Water News - Science, Technology and Politics

Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once

credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly

paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Libyan marine rescue zone aims to 'organise' NGOs: navy

Mass burials begin for 400 Sierra Leone flood victims

Urban flooding on the rise, as countryside dries up

Hunter fells elephant that killed 15 in India

Surprise discovery in the search for energy efficient information storage

Electricity and silver effective at keeping bacteria off plastics

Researchers 3-D print first truly microfluidic 'lab on a chip' devices

2-faced 2-D material is a first at Rice

New technique offers clues to measure the deoxygenation of the ocean

Meadow of dancing brittle stars shows evolution at work

Ancient ocean deoxygenation provides an urgent warning

Japan launches study into suspected Chinese coral poaching

Melting of Greenland glacier to speed up: study

Scientists are recruiting Alaskans to help them track berry patches

Not all glaciers in Antarctica have been affected by climate change

Extreme melt season leads to decade-long ecosystem changes in Antarctic polar desert

Oceans possess vast, untapped potential for sustainable aquaculture

Efforts to reduce pollution from agriculture paying off slowly

'Inefficient' sailing fleet keeps oyster fishery alive

Climate change will cut crop yields: study

Climate change shifts timing of European floods

Hurricane Gert churns up dangerous swells on US east coast

At least 221 dead in India, Bangladesh, Nepal floods

Sierra Leone appeals for urgent help after deadly floods

Dalai Lama cancels Botswana trip with 'exhaustion'

UN says Nigeria relations 'intact' after unauthorised raid

Nigerian forces in 'unauthorised search' of UN camp

Kenyan opposition demands Odinga be 'declared president'

New 13-million-year-old infant skull sheds light on ape ancestry

Arrival of modern humans in Southeast Asia questioned

Research reveals how neurons communicate

Ancient infant skull yields insights into human-ape lineage

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement