Hexbyte Glen Cove Bones of whale extinct for 300 years that were once stored in North Carolina couple’s garage are headed for Smithsonian

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A couple walking on a North Carolina beach made a rare discovery that could help researchers solve mysteries from long ago.

Rita and Tom McCabe were used to finding shells during their walks on West Onslow Beach in the 1970s—but then they started stumbling upon large bones. After years of keeping the remains in their garage, the couple gave them to the University of North Carolina, Wilmington.

It turns out, the bones belonged to a extinct for about 300 years.

“We grew very excited because there was very little scientific information on the North Atlantic because it was no longer here,” David Webster, a longtime professor and senior associate dean for the College of Arts and Sciences at UNCW, said in a news release.

The whale specimen—believed to be the “most complete” of its kind—found a new home at UNCW, where it remained for decades.

Now officials say the bones began a new chapter at the Smithsonian in late 2021.

Webster said he thinks the couple, who have both since died, would find joy in knowing their collection could continue to help researchers.

“I’m sure they are just tickled pink,” he said in the news release. “They are probably saying, ‘Can you believe it? We made it big time.'”

The Smithsonian said it hopes the donated specimen will help offer clues about North Atlantic gray whales and what life was like hundreds of years ago.

“Specimens like these, tie to place and time,” Nicholas Pyenson, curator of fossil marine mammals at the National Museum of Natural History, said in a Smithsonian Ocean article. “They tell us how the world once was.”

The museum will have the bones on display, according to UNCW. But getting the massive load more than 300 miles from North Carolina to Washington, D.C., was no easy feat.

The bones were loaded onto a van that “looked more like a minibus” and were cushioned with “layers and layers of bubble wrap,” David Bohaska, a vertebrate paleontology collections specialist, told Smithsonian Ocean.

The journey was reminiscent of the time the couple first dropped the bones off at UNCW.

“They drove a small Chevy S10 pickup truck to campus, and they had bones hanging out all over the place,” Webster said in the news release for the school, which today has about 18,000 students.

After initially thinking the specimen was a humpback whale, researchers said closer examination revealed a more rare surprise. The bones have stains that helped them determine where the animal may have been.

“UNCW researchers discovered through radiocarbon tests that the bones are hundreds of years old and probably washed ashore after the young whale died of during a migration period,” the college said. “They theorize that the carcass floated into the New River Inlet and ended up in the nearby salt marshes.”

The remains, found along West Onslow Beach near the Camp Lejeune military base, also have marks that indicate Native Americans may have butchered the whale after it died, UNCW professor David La Vere said in the news release.

North Atlantic gray weighed up to 90,000 pounds and were found in the northern part of the world before they were last seen in the 1700s. Though the exact cause of their extinction isn’t known, their habitats near the shore made them vulnerable to whaling, the Smithsonian Ocean website said.



2022 Miami Herald. Distributed by Tribune Content Agency, LLC.

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Bones of whale extinct for 300 years that were once stored in North Carolina couple’s garage are headed for Smithsonian (2022, January 12)

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Hexbyte Glen Cove Time-expanded phase-sensitive optical time-domain reflectometry thumbnail

Hexbyte Glen Cove Time-expanded phase-sensitive optical time-domain reflectometry

Hexbyte Glen Cove

(a) Working principle of the TE-?OTDR technique. The fiber under test is probed by an optical frequency comb with a tooth spacing and a random spectral phase profile. The impulse response of the fiber is encoded on the backscattered signal generated by the propagation of the probe comb. This signal is beaten with a local oscillator, which is another optical frequency comb with the same random spectral phase profile. The LO and the probe comb are composed of the same number of lines, but the line spacing of the LO is slightly higher by an amount . The detection stage consists in a balanced photodetector followed by an electrical low-pass filter. The beating between lines of the probe comb and the neighboring lines of the LO comb results in a radiofrequency comb with a tooth spacing that is given by . This entails a down-conversion of the optical bandwidth, being the compression factor CF the ratio between and . Alternatively, the above process can be understood in the time domain as a large time expansion of the detected signal. (b) Temperature map of a hot point with 2 cm of length measured by the TE-OTDR scheme. A perturbation of 0.2 Hz is recovered. (c) Dynamic strain map around a 4 cm of length obtained by means of the range-extended TE-OTDR scheme. A perturbation of 5 Hz is recovered in this case. Credit: Miguel Soriano-Amat, Hugo F. Martins, Vicente Durán, Luis Costa, Sonia Martin-Lopez, Miguel Gonzalez-Herraez and María R. Fernández-Ruiz

Distributed optical fiber sensing (DOFS) is currently a mature technology that allows ‘transforming’ a conventional fiber optic into a continuous array of individual sensors, which are distributed along its length. Between the panoply of techniques developed in the field of DOFS, those based on phase-sensitive optical time-domain reflectometry (ΦOTDR) have gained a great deal of attention, mainly due to their ability to measure strain and temperature perturbations in real time. These unique features, along with other advantages of distributed sensors (reduced weight, electromagnetic immunity and small size) make ΦOTDR sensors an excellent solution for monitoring large infrastructures (like bridges and pipelines), especially when considering that their cost scales inversely to the number of sensing points, and its resolution can achieve a few meters.

In a new paper published in Light Science & Applications, a team of scientists from the University of Alcalá, University Jaume I and the Spanish Research Council (CSIC) presents a novel fiber optic interrogator to conduct ΦOTDR. It is based on a well-known interferometric technique that employs two mutually coherent optical frequency combs. This new interrogator allows strain and/or temperature sensing with resolutions on the cm scale over up to 1 km range (i.e., it provides >104 sensing points distributed along the ). In view of the reported results, this approach opens up the door for cost-effective DOFS in short range and high-resolution applications, such as structure health monitoring of aerospace components and wellbore production surveillance, which to date have a prohibitive cost.

The technique presented in the paper, called time-extended ΦOTDR (TE-ΦOTDR), relies on the use of a smartly engineered ultra-dense optical frequency comb to probe a sensing fiber. A weak return signal is then originated by the elastic scattering experienced by the light. This signal is detected by making it interfere with a second comb, which has a bandwidth and spectral phase coding similar to that of the probe, but a different tooth spacing. The result is a multi-heterodyne interference that produces a “time extension” of the detected signals (see Figure). In the frequency domain, this process can be understood as a frequency ‘down-conversion’ (an optical-to-electrical mapping). In the dual-comb scheme developed for DOFS, both combs are generated from the same continuous wave laser, thanks to a couple of electro-optical modulators driven by a single arbitrary waveform generator.

Some remarkable features of this scheme are: (i) the flexibility in the design of the combs, which allows the user to achieve the targeted performance for the sensor; (ii) the reduced detection bandwidth (in the sub-megahertz regime for centimeter resolution over 200 meters), which is a consequence of the time-extension experienced by the detected signals; and (iii) the capability of maximizing the power injected into the sensing fiber. This last feature is fundamental to carry out real distributed sensing, given the extreme weakness of the elastic scattering phenomenon. By introducing a controlled random phase profile in the generated combs, the peak power of the optical signals can be minimized, while preserving a high average power to improve the sensor’s signal to noise ratio. In addition, the encoded phase is automatically demodulated upon detection, requiring no further post-processing.

“The sensing scheme based on a conventional dual-comb scheme allows us to reach cm-scale resolutions over sensing ranges of a few hundreds of meters, while keeping a measurement rate of tens of hertz. In the paper, we also introduce a strategy to significantly extend the sensing range without reducing the acoustic sampling rate. The basic idea is to employ two frequency combs with very dissimilar tooth spacing, so the generated time signals have quasi-integer-ratio periods. This scheme, previously applied to the field of spectroscopy, makes it possible to measure fibers up to 1 km length with a spatial resolution of 4 cm. This means 25,000 individual sensing points along the fiber. This performance improvement is at the cost of increasing to some extent the detection bandwidth (up to a few megahertz), as well as the complexity of the processing algorithm, although still retaining the fundamental advantages of the method.”

“The presented techniques expose a completely new operation arena for dynamic ΦOTDR-based sensors, which was limited to fields requiring sensing along tens of kilometers and meter-scale resolutions to arise as a worthwhile solution. The results demonstrated in the paper are a promising step to design distributed sensor providing fast acquisition speed, small detection bandwidth and sharp spatial resolution,” they added.



More information:
Miguel Soriano-Amat et al, Time-expanded phase-sensitive optical time-domain reflectometry, Light: Science & Applications (2021). DOI: 10.1038/s41377-021-00490-0

Citation:
Time-expanded phase-sensitive optical time-domain reflectometry (2021, March 23)
retrieved 23 March 2021
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