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A couple years back, I presented a lecture to the Society of Diagnostic Medical Sonography (SDMS) Annual Convention titled Ultrasound: Changing the World.  My focus then was on how changes in access to our technology portends revolutionary advancement in patient care to areas of the world that are historically “under-served”.

For the majority of ultrasound studies, , the patient is laying on an exam table.  Recently however, scientists used ultrasound interpretive strategies to interrogate and visualize a much larger “patient”.  Surveying decades of seismic data collected from around the world, researchers noted sound waves traveling unexpectedly faster through specific regions of the Earth’s subsurface.

Speed Error associated with a needle

They were confronted with a phenomenon familiar to most experienced sonographers: speed error.  So, when sound waves are not behaving how we expect, our first step is to reexamine our assumptions, which is what these researchers did as well.

In this case, they concentrated on the medium through which the sound waves were passing. Specifically these were the lower regions of the continental lithosphere called cratons, which extend like roots into Earth’s mantle.  As sound was traveling faster than anticipated, scientist drew the conclusion that density within these formations was higher than their underlying assumptions.  This led them to conclude that cratons must contain diamonds in a higher proportion than previously thought, nearly 1000 times more.

Sadly, the technology does not exist yet to access these deposits, which lie nearly 100-150 miles below the Earth’s surface. However, it is nice to know that whether you are interrogating an 8000 mile wide planet, or a 160 lb. patient, the principles of physics are the same.  The propagation of sound waves provides valuable information, and your experience and deductive reasoning help you reach the appropriate conclusions.

–Frank Miele, MSEE , President of Pegasus Lectures, Inc.  Frank graduated cum laude from Dartmouth College with a triple major in physics, mathematics, and engineering. While at Dartmouth, he was a Proctor Scholar and received citations for academic excellence in comparative literature, atomic physics and quantum mechanics, and real analysis. Frank was a research and design engineer and project leader, designing ultrasound equipment and electronics for more than ten years at Hewlett Packard Company. As a designer of ultrasound, he has lectured across the country to sonographers, physicians, engineers and students on myriad topics.

For more details on the research study:

http://news.mit.edu/2018/sound-waves-reveal-diamond-cache-deep-earths-interior-0716