APRIL/MAY 2007 VOLUME 1, NUMBER 1
Sonar Scanner Provides Complete Picture
SSonar Scanner Provides Complete Picture
Once the structural inspection was
chool buses cross bridges every day. But
complete, Abbott used acoustic underwater
how do we know when a bridge is no longer
imaging to determine any scour present on the
safe? How would anyone know if the foundation
river bed. Using a sonar scanner to take pictures
of a bridge were cracking underwater?
of the piers from various
The maintenance of
distances and angles,
bridges and roads falls
Abbott was able to create
under the responsibility
a complete picture of the
of state or federal
river bed, identify debris
departments of
around the piers and
transportation. In the
determine the effects of
spring of 2006, the
scouring (Picture 1). After
Michigan Department of
creating a series of side
Transportation (DOT)
view images from 360
hired professional diver
degrees around the
and MTS member Brian
foundation, Abbott used
Abbott and his company,
Adobe Photoshop to
Nautilus Marine Group,
combine them to produce
to perform an inspection
an overhead picture of
of the Independence and
each pier (see Picture 2).
Liberty Bridges in Bay
Abbott is one of the first
City.
people in the world to use
Using a team of four
this technique to examine
divers, Abbott examined Brian Abbott prepares for the plunge.
an entire structure.
the bridges using both
Using surface-supplied air diving and this
surface supplied air diving and underwater
new application of underwater imaging, Abbott
acoustic imaging. A color camera was mounted
was able to detect and detail the structural
on one diver’s helmet, but there was so much
problems and deterioration of the Independence
sediment suspended in the river that the
and Liberty Bridges. The Michigan DOT is
pictures were of little use. The divers countered
preparing to repair the bridges. Thanks to
the poor visibility by performing tactile
inspections of the piers.
Continued on page 2
KEY TERMS
What is Sonar?
Sonar stands for SOund NAvigation and Ranging. Sonar instruments can be passive or active. Passive sonar
reacts to sounds in the ocean, like underwater explosions, earthquakes, volcanic eruptions, sounds produced by
fish and other animals or ships. Active sonar sends sound waves toward objects, then records what the sounds
are like when they come back to the instrument. Objects in the ocean can transmit, absorb and reflect sound
waves. Density affects sound speed, and sound speed is slower in fresh water than in sea water. There are
many kinds of sonar, each developed for a different task. For example in side scan sonar, the sonar device is
attached to the hull of a ship or towed behind a ship and emits fan-shaped pulses down toward the seafloor.
Side scan sonar is used for such things as mapping the ocean floor, searching for sunken ships and inspecting
undersea pipelines and cables. The study of underwater sound is called hydroacoustics.
Continued on page 2
Career Corner
Diving into a Marine Technology Career
I
nterested in making diving a part of your career in marine technology? There are a number of
options available in commercial, research and military diving.
Brian Abbott is an example of a commercial diver. A civil engineer who is also an expert diver,
he uses his skill set not only to inspect bridges and other structures, but also to perform navigational
charting, channel maintenance, construction management, pipeline routing and archaeology.
Typically, engineering positions require a four-year
degree in mechanical, structural, marine or ocean
engineering. Phoenix International is a marine
engineering company and an MTS member.
According to the company’s Mechanical Engineering
Manager Craig Kohler, diver certification and
experience are not requirements for Phoenix’s
engineers, but are certainly highly valued
credentials. Kohler’s engineers develop and design
underwater systems, tools and methods for
performing offshore inspections. Kohler has found
that experienced divers, having spent so much time
in the water, are better equipped to understand the
necessities of the job when designing systems.
Research diving is a field that generally
requires an advanced degree in oceanography or
another related discipline. Research divers are
typically employed by academic institutions or
government agencies. Students who have received their master’s degrees often secure jobs as
diving technicians at their academic institutions as they pursue their doctoral degrees. A research
diver employed by an academic institution normally spends significant time teaching in the
classroom as well as doing research in the field.
Military diving offers the privilege of serving your country while enjoying a career in diving and
marine technology. There is a wide variety of specialties available to divers in the military. Navy
divers perform underwater maintenance and repair of ships, salvage operations, surveying and
research, deep submergence rescue, construction and explosive ordnance disposal.
Diving is a skill that can lead to a number of exciting career paths in marine technology.
Did you know?
MTS Club News is a bimonthly
publication of the
Marine Technology Society
and a member benefit of the MTS Club.
The minimum age to become a certified SCUBA
diver is 10 years old. If you are interested in training
to become a certified diver, visit www.padi.com.
To join the MTS Club, visit the Web site
at www.mtsociety.org/youthclub.cfm
or e-mail [email protected].
Send address changes
to [email protected].
2
1
2
Sonar Scanner
Continued from page 1
innovative methods like Abbott’s, advanced
marine technology plays an important role in
ensuring the safety of people who cross that
bridge.
The Marine Technology Society has both a
Diving Committee and an Underwater Imaging
Committee for our professional members. If you
have questions about diving, please free to
contact Diving Committee Chair Brian Abbott
([email protected]). Or, if you have questions
about underwater imaging, please contact UI
Committee Chair Donna Kocak
([email protected]).
KEY TERMS
Continued from page 1
www.mtsociety.org/
youthclub.cfm
Underwater Acoustic Imaging is used to
produce high-quality images in water where
visibility is too poor to use optical methods. In
underwater acoustic imaging, electrical energy
(electricity) is sent to a crystal, which causes the
crystal to vibrate. The sound of the vibration
(mechanical energy) travels out into the water
Continued on page 3
Here are a few fun and free things you can
do online.
Learn about Woods Hole Oceanographic
Institution (WHOI) expeditions that use deepsea tools and vehicles. The current expedition is
exploring the Arctic. Web link:
www.divediscover.whoi.edu
California engineer Mark Fischer uses
wavelets—a technique for rocessing digital
signals—to transform the haunting calls of
ocean mammals into movies that visually
represent the songs and still images that look
like electronic mandalas. Web link:
www.aguasonic.com.
+A cademic Arena
Are you on the
Scholarship Bus?
We are looking for promising high school seniors who are interested in studying marine
technology next year. The Marine Technology Society offers thousands of dollars in scholarships to
graduating high school seniors who have been accepted into a full-time undergraduate program.
Available scholarships include:
„
„
„
$2,000 MTS Student Scholarship for Graduating High School Seniors
$2,000 Paros-Digiquartz Scholarship – open to graduate, undergraduate, and graduating
high school seniors interested in marine instrumentation
Up to $10,000 ROV Scholarship – open to graduate, undergraduate and high school
seniors interested in Remotely Operated Vehicles (ROVs) or underwater work that furthers
the work of ROVs
Take advantage of this opportunity to follow your dreams and launch your career in marine
technology. The deadline to apply for MTS Scholarships is April 16, 2007. For more information
and applications, visit the Education link on the MTS Web site:/www.mtsociety.org/education/
student_scholarships.cfm
ASK AN EXPERT
Send questions to the Club News editor at
[email protected] to have them
answered by a Marine Technology Society
expert.
A researcher takes a core sample from brain
coral. (Photo courtesy of Wolcott Henry.)
Check out live video and special content from
the National Oceanic amd Atmospheric
Administration’s (NOAA) National Marine
Sanctuaries. Web link: www.oceanslive.org.
The Center for Ocean Science Education
Excellence offers a “one-stop” Web site for
ocean careers. Web link:
www.oceancareers.com.
The California Ocean Communicators
Alliance has launched a public awareness
campaign to help Californians learn, experience
and respect the oceans. Web link:
www.ThankYouOcean.org
ORBITAL (Ocean Remote-sensing Base for
Interactive Teaching And Learning) is an
interactive Web site that shows how scientists
use satellites to monitor the oceans. Web link:
education.imars.usf.edu
Marine Technology Society Expert Topics
Autonomous Underwater Vehicles (AUV)
Buoy Technology
Cables & Connectors
Dynamic Positioning
Marine Education
Marine Security
Moorings
Ocean Economic Potential
Ocean Energy
Ocean Exploration
Ocean Pollution
Oceanographic Instrumentation
Offshore Structures
Physical Oceanography/Meteorology
Remote Sensing
Ropes & Tension Member
Remotely Operated Vehicles (ROV)
Seafloor Engineering
Underwater Imaging
KEY TERMS
Continued from page 2
column until it hits an object and is reflected back to the crystal. After the energy returns to the
crystal, a computer converts it to an image.
Surface Supplied Air Diving: Divers tethered to a surface-supplied-air diving system can achieve
dives up to 190 feet of seawater (FSW) in air diving and 300 FSW in mixed gas diving. Air is
supplied via an air compressor or high-pressure air flasks. A surface-supplied-air diving system can
permit a diver to stay down for a longer period of time than a SCUBA system would allow.
Scour is the destructive effect that flowing water has on a submerged object. When a man made
object such as a bridge pier, pipeline, cable, etc. is submerged in flowing water the local
effect is to increase the current velocity around the object. This increased velocity has
the tendency to remove or scour away the bottom material that supports the structure.
3
Check out the MTS Club Web page!
www.mtsociety.org/
youthclub.cfm
Academic News
Get Your Friends to Join!
Ask the Experts
Educational and
Just-for-Fun Links
Technology
News
Keep Scrolling!
There’s a Glossary
and more news!
4