Flow dynamics and till genesis associated with a marine-based Antarctic palaeo-ice stream

first_imgGeophysical and geological data indicate that during the last glacial cycle a palaeo-ice stream drained the Antarctic Peninsula Ice Sheet (APIS) through Marguerite Bay to the edge of the continental shelf via a bathymetric trough (Marguerite Trough). Mega-scale glacial lineations (MSGL) in outer Marguerite Trough are formed in an acoustically transparent sediment unit, consisting of a soft deformation till. The association of MSGL with deformation till indicates that bed deformation occurred beneath the ice stream, and the thickness of the subglacial deforming layer was on the order of several metres. MSGL within outer Marguerite Trough are related to a pre-existing thick sequence of soft sediments on the outer shelf and are inferred to have formed by a combination of subglacial sediment deformation by attenuation from a point source and groove-ploughing. Morphologically, the MSGL differ in several respects from those documented elsewhere and this variation suggests a polygenetic origin for this subglacial landform. An initial advance of the APIS across the Marguerite Bay continental shelf at the LGM deposited a stiff subglacial till. Following this advance, the ice margin within Marguerite Trough retreated 70–100 km before stabilising and depositing a grounding zone wedge. An ice stream then developed in the trough and extended to the shelf edge forming a soft deformation till. Development of the ice stream may have been a glacio-dynamic response to regional deglaciation. Subsequent retreat of the Marguerite Trough ice stream was underway by 13,490 (uncorrected) 14C years before present. Based on the geophysical and core data, ice-stream retreat appears to have been rapid and it contrasts with reconstructions of palaeo-ice streams from other locations in Antarctica. This implies marked regional variations in Antarctic ice-stream dynamics during Late Quaternary deglaciation.last_img read more

Measurement of Prandtl number as a function of Richardson number avoiding self-correlation

first_imgThe empirical dependence of turbulence Prandtl number (Pr) on gradient Richardson number (Ri) is presented, derived so as to avoid the effects of self-correlation from common variables. Linear power relationships between the underlying variables that constitute both Pr and Ri are derived empirically from flux and profile observations. Pr and Ri are then reconstructed from these power laws, to indicate their interdependence whilst avoiding self-correlation. Data are selected according to the stability range prior to regression, and the process is iterated from neutral to higher stability until error analysis indicates the method is no longer valid. A Butterworth function is fitted to the resulting Pr (-1)(Ri) regression to give an empirical summary of the analysis. The form suggests that asymptotically Pr (-1) decreases as Ri (3/2). Scatter in the data increases above Ri similar to 1, however, indicating additional constraints to Pr are not captured by Ri alone in this high stability regime. The Butterworth function is analytic for all Ri > 0, and may be included in suitable boundary-layer parameterisation schemes where the turbulent diffusivity for heat is derived from the turbulent diffusivity for momentum.last_img read more

The origin of Jupiter’s outer radiation belt

first_imgThe intense inner radiation belt at Jupiter (>50 MeV at 1.5 RJ) is generally accepted to be created by radial diffusion of electrons from further away from the planet. However, this requires a source with energies that exceed 1 MeV outside the orbit of the moon Io at 5.9 RJ, which has never been explained satisfactorily. Here we test the hypothesis that this source population could be formed from a very soft energy spectrum, by particle injection processes and resonant electron acceleration via whistler mode chorus waves. We use the British Antarctic Survey Radiation Belt Model to calculate the change in the electron flux between 6.5 and 15 RJ; these are the first simulations at Jupiter combining wave particle interactions and radial diffusion. The resulting electron flux at 100 keV and 1 MeV lies very close to the Galileo Interim Radiation Electron model spectrum after 1 and 10 days, respectively. The primary driver for the increase in the flux is cyclotron resonant acceleration by chorus waves. A peak in phase space density forms such that inside L≈9 radial diffusion transports electrons toward Jupiter, but outside L≈9 radial diffusion acts away from the planet. The results are insensitive to the softness of the initial energy spectrum but do depend on the value of the flux at the minimum energy boundary. We conclude by suggesting that the source population for the inner radiation belt at Jupiter could indeed be formed by wave-particle interactions.last_img read more

The conservation status and priorities for albatrosses and large petrels

first_imgSeabirds are amongst the most globally-threatened of all groups of birds, and conservation issues specific to albatrosses (Diomedeidae) and large petrels (Procellaria spp. and giant petrels Macronectes spp.) led to drafting of the multi-lateral Agreement on the Conservation of Albatrosses and Petrels (ACAP). Here we review the taxonomy, breeding and foraging distributions, population status and trends, threats and priorities for the 29 species covered by ACAP. Nineteen (66%) are listed as threatened by IUCN, and 11 (38%) are declining. Most have extensive at-sea distributions, and the greatest threat is incidental mortality (bycatch) in industrial pelagic or demersal longline, trawl or artisanal fisheries, often in both national and international waters. Mitigation measures are available that reduce bycatch in most types of fisheries, but some management bodies are yet to make these mandatory, levels of implementation and monitoring of compliance are often inadequate, and there are insufficient observer programmes collecting robust data on bycatch rates. Intentional take, pollution (including plastic ingestion), and threats at colonies affect fewer species than bycatch; however, the impacts of disease (mainly avian cholera) and of predation by introduced species, including feral cats (Felis catus), rats (Rattus spp.) and house mice (Mus musculus), are severe for some breeding populations. Although major progress has been made in recent years in reducing bycatch rates and in controlling or eradicating pests at breeding sites, unless conservation efforts are intensified, the future prospects of many species of albatrosses and large petrels will remain bleak.last_img read more

NBA legend Kobe Bryant explains why he kept his tap dancing a secret

first_img FacebookTwitterLinkedInEmailDavid Livingston/Getty Images(LOS ANGELES) — Kobe Bryant revealed that although he once took up tap dancing to improve his skills, the NBA star said he felt forced to keep it a secret.Bryant spoke out about his secret lessons in an interview with Jimmy Kimmel on Tuesday, when the late-night host asked him if he had any celebrity friends who might surprise his fans.“Surprised? I don’t know. Maybe not surprised, but, you know, recently, I’ve been spending a lot of time with Debbie Allen,” Bryant said, referring to his famous dance teacher.The former Los Angeles Lakers superstar said he began tapping in 2000 when he sprained an ankle during the NBA Finals. He said the tap lessons helped him recover, improved his endurance and even built up his strengthBut he still felt embarrassed.“Well, it was kept secret for obvious reasons,” Bryant said Tuesday, adding that he had to get customized size-14 tap shoes. “I had to get them made. I can’t go to a store and be like, ‘Yeah, I’ll take those size 14s. Tap.’”He said he doesn’t consider himself an “accomplished tapper,” but does think he had some potential.“[At one point,] I could, like, tell my feet to do this, and they would actually do that,” he said. “I walked into the studio, and it’s all these, like, 6-year-olds … and these kids are looking up at me like, what in the world? What’s this grown-ass man doing in here learning tap dance?”Bryant, who revealed the secret in his new bodycare book, said spoke out about it because thought it might help young athletes.In “The Mamba Mentality: How I Play,” Bryant said he reveals other secrets about the game, but the key is to teach athletes about the importance of holistic self-care.“We psych ourselves up too much,” he said. “If you try to talk yourself into, ‘This is a big moment, it’s a big shot,’ you’re putting a lot of pressure on yourself. You’ve shot that shot hundreds and thousands of times, just shoot another one. It’s like breathing. You do it so many times, you just do it again.”Copyright © 2018, ABC Radio. All rights reserved. Written by Beau Lundcenter_img October 24, 2018 /Sports News – National NBA legend Kobe Bryant explains why he kept his tap dancing a secretlast_img read more

Tom Brady faces backlash for jumping off cliff with 6-year-old daughter

first_img FacebookTwitterLinkedInEmailJoe Faraoni / ESPN Images(NEW YORK) — New England Patriots star Tom Brady is soaking up family time this offseason, but he’s not immune from critics chiming in on his performance off the football field as a parent. Over the weekend, Brady shared a video on Instagram from his vacation in Costa Rica, showing him leaping off a rock formation with his youngest daughter.The father of three had been on the edge of the small cliff and waterfall above a natural pool where other people were seen swimming below. He joined hands with his daughter Vivian, 6, asked, “Are you ready?” counted to three, yelled “go” and the pair jumped into the water.Dwayne “The Rock” Johnson replied to the video, “You KNOW I have complete faith in you as a man, friend, player and father – but this just gave me anxiety. Geeezus,” he wrote, followed by the crying laughing and clapping emojis. Rapper Sean Combs, aka Diddy, also commented with the crying laughing emoji.Other social media followers were quick to add their thoughts in the comments, shocked at what they perceived as “irresponsible” behavior. “Not the smartest move,” one commenter said. “She could have been hurt. Next time wait to make sure she’s jumping too.” Another user took to Twitter and called on the NFL to look into his actions as punishable.The six-time Super Bowl champ previously jumped off a higher cliff in 2015, after which he tweeted, “Never doing that again!” It is unclear how high the rock face was or where in Costa Rica this weekend’s jump took place. Brady has not commented further.Copyright © 2019, ABC Radio. All rights reserved. Written by July 22, 2019 /Sports News – National Tom Brady faces backlash for jumping off cliff with 6-year-old daughtercenter_img Beau Lundlast_img read more

Prep Sports Roundup: 8/6

first_img Written by Tags: Prep Sports Roundup August 7, 2019 /Sports News – Local Prep Sports Roundup: 8/6 FacebookTwitterLinkedInEmailGirls SoccerNon-RegionSALT LAKE CITY-Caeli Sherman amassed a hat trick and the Judge Memorial Bulldogs routed Delta 6-2 Tuesday in non-region girls soccer action. Adison Nielson and Savannah Nielson each scored in the loss for the Rabbits.RICHFIELD, Utah-Kate Robinson’s hat trick led the way as the Richfield Wildcats pounded Gunnison Valley 8-0 in non-region girls soccer action Tuesday. Brittan Tait added two more goals in the rout for Richfield, while Alexis Kling, Melissa Crane and Sadie Yardley also scored for the Wildcats. Megan Terry posted the shutout for Richfield.SPANISH FORK, Utah-Millard was holding on to a close 2-1 lead at halftime before breaking the game open in the second half with five goals to beat American Leadership Academy 7-1 in non-region girls soccer action Tuesday. Brad Jameslast_img read more

Dixie State Men’s Basketball Routs Regis Saturday Evening

first_img FacebookTwitterLinkedInEmailST. GEORGE, Utah-Hunter Schofield posted 17 points and 4 rebounds on 6-8 from the field as the Dixie State Trailblazers routed Regis 73-53 Saturday at Burns Arena in Rocky Mountain Athletic Conference men’s basketball action.Jack Pagenkopf added 14 points and 7 assists for the Trailblazers, who improved to 14-3 and 9-2 in RMAC play on the season.Toni Rocak netted 18 points and 6 rebounds on 5-7 shooting in the loss for the Rangers, who fell to 10-7 and 5-6 in RMAC play.The Trailblazers shot 51.7 percent from the field in the win. Dixie State is next in action Friday and Saturday as they host Colorado Mesa and Western Colorado respectively. Written by Brad James January 19, 2020 /Sports News – Local Dixie State Men’s Basketball Routs Regis Saturday Evening Tags: Dixie State men’s basketball/Regis Rangerslast_img read more

Scoreboard roundup — 2/2/20

first_img Written by FacebookTwitterLinkedInEmailiStock(NEW YORK) — Here are the scores from Sunday’s sports events:NATIONAL BASKETBALL ASSOCIATIONDetroit 128, Denver 123 — OTHouston 117, New Orleans 109Milwaukee 129, Phoenix 108Toronto 129, Chicago 102NATIONAL HOCKEY LEAGUEPittsburgh 4, Washington 3Columbus 4, Montreal 3Carolina 4, Vancouver 3 — SONATIONAL FOOTBALL LEAGUE PLAYOFFSKansas City 31, San Francisco 20TOP-25 COLLEGE BASKETBALLIowa 72, Illinois 65Copyright © 2020, ABC Audio. All rights reserved. Beau Lundcenter_img February 3, 2020 /Sports News – National Scoreboard roundup — 2/2/20last_img

Simone Biles talks image expectations and ignoring the trolls

first_imgMarch 6, 2020 /Sports News – National Simone Biles talks image expectations and ignoring the trolls FacebookTwitterLinkedInEmailABC News(NEW YORK) — Simone Biles, a vocal advocate for many women’s issues, frequently calls out injustice and continually uses her platform to educate and inspire.The latest cause she is dedicating herself to is championing individuality and eradicating competition in a realm where the perfect score doesn’t exist — beauty.In a recent interview with ABC News’ Good Morning America, Biles, who is the world’s most decorated female gymnast in history, spoke about how social media hate has affected her throughout her prestigious career — and what she wishes people would consider before commenting on her appearance.“In the beginning, I would go look through comments, and I would cry, or maybe I would comment back to some,” she said. “But now I feel like if they even comment, it’s for attention, so I don’t even want to give them the time of day.”Biles said if she could go back in time, she would tell her younger self to stop putting so much attention on the trolls.“I really started to study them,” she said. “If they were like, ‘Oh, your nose is too big,’ I was like, ‘Oh my gosh, you’re right, it is too big.’ I feel like I really started to study those, and now I don’t care.”However, she admitted that sometimes hateful remarks on social media can affect her.“I feel like any negativity that comes your way is a little bit effective, even if it’s people that you don’t know. It’s from people that you think should care, so it is hurtful at times,” Biles said.To stay grounded, she said she always tries to remember, “At the end of the day, they don’t know who I really am, rather than looks and what I’ve achieved.”Exposure to these critics from such a young age has helped Biles to develop a “strong bone,” she said. The gymnast also credits positive female figures and influences in her life for helping her find her confidence.“I feel like for growing a strong bone and not caring about what people think, definitely Chrissy Teigen,” Biles said on who inspires her. “But who has helped shape me into thinking I’m beautiful with or without makeup was definitely Aly Raisman. She played a huge role in that.”“She never wore a lot of makeup and always felt beautiful,” Biles said about Raisman, her Olympic teammate. “And she always told all of us that we are beautiful, doesn’t matter what you look like, but your soul is beautiful. And then that leads to the outside and you start glowing. And that really resonated with me.”Biles said she and her teammates could at times, “find comedy in some of the comments.”“We’ll see like, ‘Oh, your calves are too big.’ And then we’re just like, ‘What? But I wouldn’t be able to tumble, like that’s the beauty of it,’” she said. “Or some people make comments and then you look at their profile and you’re like, ‘Wait, I don’t get why you’re commenting to me.’ Some of it is a little bit crazy and off the wall, but I mean, it’s whatever makes them feel better. At the end of the day, we kind of just brush it off, because, you know, we were built like this for a reason. And that’s what we do.”Looking ahead to the 2020 Summer Olympics in Tokyo, Biles realizes that she and her teammates will be in the public eye more and studied to an even greater extent. She’s hopeful that viewers will remember, “We’re people — we’re human, we have feelings too.”“We do see some of the comments you guys write, so just be a little bit more mindful,” she added. “But we’ll also do our part and we’ll try to be mindful — not comment back, not let it affect us and just go out there and do what we’re supposed to do.”Biles recently partnered with skin care brand SK-II to highlight her mission to challenge beauty standards. In one of the campaign videos, an animated version of Biles fights against a “beauty troll,” which is made up of negative tweets that have actually been written about the gymnast.At the time of announcing the partnership, Biles also penned an emotional letter about how much competition has influenced her life and shaped her perspective.“Let’s talk about competition,” she wrote. “Specifically, the competition I didn’t sign up for and feel like has become almost a daily challenge for me. And I do not think I’m the only one.”The 22-year-old explained the downside of the attention she’s experienced outside of her profession.“I’m talking about beauty,” she said. “I don’t know why but others feel as though they can define your own beauty based on their standards.”She shared how much these standards have taken a toll on her mental state throughout her life.“I’ve learned to put on a strong front and let most of it slide. But I’d be lying if I told you that what people say about my arms, my legs, my body … of how I look like in a dress, leotard, bathing suit or even in casual pants hasn’t gotten me down at times,” Biles said.The #NOCOMPETITION campaign also stars athletes who have dealt with similar pressures in their respective sports, including hurdler Liu Xiang, table tennis player Kasumi Ishikawa and badminton players Ayaka Takahashi and Misaki Matsutomo, among others.Biles believes it’s important to use her platform to speak about the toxic culture that often exists when examining beauty standards and expectations. She said what’s most important is that women remember, “It doesn’t matter what you look like on the outside — it’s about how well you do.”“So if you’re doing your job — you’re bringing back medals, you’re having fun — then you’ve done your job,” she added. “Your appearance doesn’t matter.”Copyright © 2020, ABC Audio. All rights reserved. Beau Lundcenter_img Written bylast_img read more