scholarly journals Seismic observations of crevasse growth following rain-induced glacier acceleration, Haupapa/Tasman Glacier, New Zealand

2021 ◽  
Author(s):  
S Taylor-Offord ◽  
Huw Horgan ◽  
John Townend ◽  
JP Winberry
Keyword(s):  
New Zealand ◽  
Rain Rate ◽  
Ice Sheets ◽  
Seismicity Rate ◽  
Creative Commons ◽  
Acceleration Rate ◽  
Order Of Magnitude ◽  
Strain Rate Field ◽  
Magnitude Increase ◽  
Open Access Article

Copyright © The Author(s) 2019 This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.. Changing rates of water input can affect both the flow of glaciers and ice sheets and their propensity to crevasse. Here we examine geodetic and seismic observations during two substantial (10-18-times background velocity) rain-induced glacier accelerations at Haupapa/Tasman Glacier, New Zealand. Changes in rain rate result in glacier acceleration and associated uplift, which propagate down-glacier. This pattern of acceleration results in a change to the strain rate field, which correlates with an order of magnitude increase in the apparent seismicity rate and an overall down-glacier migration in located seismicity. After each acceleration event the apparent seismicity rate decreases to below the pre-acceleration rate for 3 days. This suggests that seismic events associated with surface crevasse growth occur early during phases of glacier acceleration due to elevated extensional stresses, and then do not occur again until stresses recover.

scholarly journals Seismic observations of crevasse growth following rain-induced glacier acceleration, Haupapa/Tasman Glacier, New Zealand

2021 ◽  
Author(s):  
S Taylor-Offord ◽  
Huw Horgan ◽  
John Townend ◽  
JP Winberry
Keyword(s):  
New Zealand ◽  
Rain Rate ◽  
Ice Sheets ◽  
Seismicity Rate ◽  
Creative Commons ◽  
Acceleration Rate ◽  
Order Of Magnitude ◽  
Strain Rate Field ◽  
Magnitude Increase ◽  
Open Access Article

Copyright © The Author(s) 2019 This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.. Changing rates of water input can affect both the flow of glaciers and ice sheets and their propensity to crevasse. Here we examine geodetic and seismic observations during two substantial (10-18-times background velocity) rain-induced glacier accelerations at Haupapa/Tasman Glacier, New Zealand. Changes in rain rate result in glacier acceleration and associated uplift, which propagate down-glacier. This pattern of acceleration results in a change to the strain rate field, which correlates with an order of magnitude increase in the apparent seismicity rate and an overall down-glacier migration in located seismicity. After each acceleration event the apparent seismicity rate decreases to below the pre-acceleration rate for 3 days. This suggests that seismic events associated with surface crevasse growth occur early during phases of glacier acceleration due to elevated extensional stresses, and then do not occur again until stresses recover.

scholarly journals Seismic observations of crevasse growth following rain-induced glacier acceleration, Haupapa/Tasman Glacier, New Zealand

2019 ◽  
Vol 60 (79) ◽  
pp. 14-22
Author(s):  
Samuel Taylor-Offord ◽  
Huw Horgan ◽  
John Townend ◽  
J. Paul Winberry
Keyword(s):  
New Zealand ◽  
Strain Rate ◽  
Rain Rate ◽  
Ice Sheets ◽  
Seismic Events ◽  
Seismicity Rate ◽  
Acceleration Rate ◽  
Order Of Magnitude ◽  
Strain Rate Field ◽  
Magnitude Increase

ABSTRACTChanging rates of water input can affect both the flow of glaciers and ice sheets and their propensity to crevasse. Here we examine geodetic and seismic observations during two substantial (10–18-times background velocity) rain-induced glacier accelerations at Haupapa/Tasman Glacier, New Zealand. Changes in rain rate result in glacier acceleration and associated uplift, which propagate down-glacier. This pattern of acceleration results in a change to the strain rate field, which correlates with an order of magnitude increase in the apparent seismicity rate and an overall down-glacier migration in located seismicity. After each acceleration event the apparent seismicity rate decreases to below the pre-acceleration rate for 3 days. This suggests that seismic events associated with surface crevasse growth occur early during phases of glacier acceleration due to elevated extensional stresses, and then do not occur again until stresses recover.

scholarly journals Analyses of phenotypic differentiations among South Georgian Diving Petrel (Pelecanoides georgicus) populations reveal an undescribed and highly endangered species from New Zealand

2020 ◽  
Author(s):  
Johannes Fischer ◽  
I Debski ◽  
CM Miskelly ◽  
CA Bost ◽  
A Fromant ◽  
...  
Keyword(s):  
New Zealand ◽  
Principal Component ◽  
Breeding Habitat ◽  
Species Status ◽  
Breeding Colony ◽  
Creative Commons ◽  
Zealand Population ◽  
Species Being ◽  
Open Access Article ◽  
Diving Petrel

© 2018 Fischer et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Unresolved taxonomy of threatened species is problematic for conservation as the field relies on species being distinct taxonomic units. Differences in breeding habitat and results from a preliminary molecular analysis indicated that the New Zealand population of the South Georgian Diving Petrel (Pelecanoides georgicus) was a distinct, yet undescribed, species. We measured 11 biometric characters and scored eight plumage characters in 143 live birds and 64 study skins originating from most populations of P. georgicus, to assess their taxonomic relationships. We analysed differences with principal component analyses (PCA), factorial ANOVAs, and Kruskal-Wallis rank sum tests. Results show that individuals from New Zealand differ significantly from P. georgicus from all other populations as following: 1) longer wings, 2) longer outer tail feathers, 3) deeper bills, 4) longer heads, 5) longer tarsi, 6) limited collar extent, 7) greater extent of contrasting scapulars, 8) larger contrasting markings on the secondaries, 9) paler ear coverts, 10) paler collars, and 11) paler flanks. Furthermore, we used a species delimitation test with quantitative phenotypic criteria; results reveal that the New Zealand population of P. georgicus indeed merits species status. We hereby name this new species Pelecanoides whenuahouensis sp. nov. Due to severe reductions in its range and the very low number of remaining birds (~150 individuals limited to a single breeding colony on Codfish Island/Whenua Hou) the species warrants listing as ‘Critically Endangered’. An abstract in the Māori language/Te Reo Māori can be found in S1 File.

scholarly journals Analyses of phenotypic differentiations among South Georgian Diving Petrel (Pelecanoides georgicus) populations reveal an undescribed and highly endangered species from New Zealand

2020 ◽  
Author(s):  
Johannes Fischer ◽  
I Debski ◽  
CM Miskelly ◽  
CA Bost ◽  
A Fromant ◽  
...  
Keyword(s):  
New Zealand ◽  
Principal Component ◽  
Breeding Habitat ◽  
Species Status ◽  
Breeding Colony ◽  
Creative Commons ◽  
Zealand Population ◽  
Species Being ◽  
Open Access Article ◽  
Diving Petrel

© 2018 Fischer et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Unresolved taxonomy of threatened species is problematic for conservation as the field relies on species being distinct taxonomic units. Differences in breeding habitat and results from a preliminary molecular analysis indicated that the New Zealand population of the South Georgian Diving Petrel (Pelecanoides georgicus) was a distinct, yet undescribed, species. We measured 11 biometric characters and scored eight plumage characters in 143 live birds and 64 study skins originating from most populations of P. georgicus, to assess their taxonomic relationships. We analysed differences with principal component analyses (PCA), factorial ANOVAs, and Kruskal-Wallis rank sum tests. Results show that individuals from New Zealand differ significantly from P. georgicus from all other populations as following: 1) longer wings, 2) longer outer tail feathers, 3) deeper bills, 4) longer heads, 5) longer tarsi, 6) limited collar extent, 7) greater extent of contrasting scapulars, 8) larger contrasting markings on the secondaries, 9) paler ear coverts, 10) paler collars, and 11) paler flanks. Furthermore, we used a species delimitation test with quantitative phenotypic criteria; results reveal that the New Zealand population of P. georgicus indeed merits species status. We hereby name this new species Pelecanoides whenuahouensis sp. nov. Due to severe reductions in its range and the very low number of remaining birds (~150 individuals limited to a single breeding colony on Codfish Island/Whenua Hou) the species warrants listing as ‘Critically Endangered’. An abstract in the Māori language/Te Reo Māori can be found in S1 File.

scholarly journals Hydraulic transmissivity inferred from ice-sheet relaxation following Greenland supraglacial lake drainages

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ching-Yao Lai ◽  
Laura A. Stevens ◽  
Danielle L. Chase ◽  
Timothy T. Creyts ◽  
Mark D. Behn ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Ice Sheet ◽  
Drainage System ◽  
Greenland Ice Sheet ◽  
Field Observations ◽  
Surface Uplift ◽  
Drainage Networks ◽  
Order Of Magnitude ◽  
Lake Drainage ◽  
Magnitude Increase

AbstractSurface meltwater reaching the base of the Greenland Ice Sheet transits through drainage networks, modulating the flow of the ice sheet. Dye and gas-tracing studies conducted in the western margin sector of the ice sheet have directly observed drainage efficiency to evolve seasonally along the drainage pathway. However, the local evolution of drainage systems further inland, where ice thicknesses exceed 1000 m, remains largely unknown. Here, we infer drainage system transmissivity based on surface uplift relaxation following rapid lake drainage events. Combining field observations of five lake drainage events with a mathematical model and laboratory experiments, we show that the surface uplift decreases exponentially with time, as the water in the blister formed beneath the drained lake permeates through the subglacial drainage system. This deflation obeys a universal relaxation law with a timescale that reveals hydraulic transmissivity and indicates a two-order-of-magnitude increase in subglacial transmissivity (from 0.8 ± 0.3 $${\rm{m}}{{\rm{m}}}^{3}$$ m m 3 to 215 ± 90.2 $${\rm{m}}{{\rm{m}}}^{3}$$ m m 3 ) as the melt season progresses, suggesting significant changes in basal hydrology beneath the lakes driven by seasonal meltwater input.

scholarly journals Review of the soft-X-ray laser research at CEL-V

1991 ◽  
Vol 9 (2) ◽  
pp. 493-499
Author(s):  
D. Naccache ◽  
J-L. Bourgade ◽  
P. Combis ◽  
C. J. Keane ◽  
J-P. Le Breton ◽  
...  
Keyword(s):  
Atomic Number ◽  
Collisional Excitation ◽  
X Ray ◽  
Order Of Magnitude ◽  
Laser Experiments ◽  
Magnitude Increase

We present some significant results of collisional excitation X-ray laser experiments in plasmas produced by a laser. We studied the amplification in Ne- and Ni-like ions by varying both the nature and the thickness of targets, the irradiation, and the wavelength of the driving laser. Some potentially interesting scalings as a function of the atomic number of the lasing element are demonstrated in the Ne-like system. An order-of-magnitude increase in gain in the Ni-like experiments was determined.

Critical current density and microstructure variations in YBa2Cu3O7−x + BaSnO3 films with different concentrations of BaSnO3

2008 ◽  
Vol 23 (12) ◽  
pp. 3363-3369 ◽  
Author(s):  
C.V. Varanasi ◽  
J. Burke ◽  
L. Brunke ◽  
H. Wang ◽  
J.H. Lee ◽  
...  
Keyword(s):  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Gradual Increase ◽  
Critical Transition ◽  
Critical Transition Temperature ◽  
Transmission Electron ◽  
Order Of Magnitude ◽  
High Fields ◽  
Magnitude Increase

Previous work on YBa2Cu3O7−x (YBCO) + BaSnO3 (BSO) films with a single composition showed significant critical current density (Jc) improvements at higher fields but lowered Jc in low fields. A detailed study on BSO concentrations provided here demonstrates that significant Jc enhancement can occur even up to 20 mol% BSO inclusion, where typical particulate inclusions in these concentrations degrade the YBCO performance. YBCO + BSO films were processed on (100) LaAlO3 substrates using premixed targets of YBa2Cu3O7-x (YBCO) with additions of 2, 4, 10, and 20 mol% BSO. The critical transition temperature Tc of the films remained high (>87 K), even with large amounts (20 mol%) of BSO. YBCO + BSO films showed a gradual increase in Jc at high fields as the amount of BSO was increased. More than an order of magnitude increase in Jc was measured in YBCO + BSO samples as compared to regular YBCO at 4 T. YBCO + 10 mol% BSO films showed overall improvement at all the field ranges while YBCO + 20 mol% BSO was better only at high fields. Transmission electron microscopy revealed the presence of ∼7–8-nm-diameter BSO nanocolumns, the density of which increased with increasing BSO content correlating well with the observed improvements in Jc.

scholarly journals Research on the Correlation of Serum PCT and Plasma GSN Levels with the Prognosis of Urosepsis Patients

2020 ◽  
Vol 36 (5) ◽  
Author(s):  
Na Cui ◽  
Zhanbiao Yu ◽  
Zhi Chen ◽  
Ning Chen
Keyword(s):  
Poor Prognosis ◽  
Original Work ◽  
Protective Factor ◽  
Good Prognosis ◽  
Control Group ◽  
Creative Commons ◽  
The Poor ◽  
Prognosis Group ◽  
Good Prognosis Group ◽  
Open Access Article

Objective: To explore the correlation of procalcitonin (PCT) and gelsolin (GSN) with the prognosis of urosepsis patients. Method: The data of 71 urosepsis patients from March 2015 to April 2019 who were admitted to and treated in Affiliated Hospital of Hebei University were analyzed and compared with those of 92 healthy persons. Serum PCT and plasma GSN levels at different times after treatment were detected. According to prognosis, patients were classified into the good prognosis group or the poor prognosis group. The serum PCT and plasma GSN levels of both groups were compared. Result: The serum PCT level of the urosepsis group on the 1st, 3rd, 5th and 7th days was obviously higher than that of the control group (P<0.05). The plasma GSN levels of the urosepsis group on the 1st, 3rd, 5th and 7th days were obviously lower than those of the control group (P<0.05).The serum PCT level of the poor prognosis group on the 1st, 3rd, 5th and 7th days was obviously higher than that of the good prognosis group (P<0.05). The plasma GSN level of the poor prognosis group on the 1st, 3rd, 5th and 7th days was obviously lower than that of the good prognosis group (P<0.05). PCT was an independent risk factor influencing the prognosis of urosepsis patients and that GSN was a protective factor (P<0.05). Conclusion: The serum PCT and plasma GSN levels can accurately predict the severity and prognosis of urosepsis patients and reflect the disease state of early urosepsis patients. High PCT levels and low GSN levels indicate poor prognosis, and clinicians should consider these values. doi: https://doi.org/10.12669/pjms.36.5.2143 How to cite this:Cui N, Yu Z, Chen Z, Chen N. Research on the Correlation of Serum PCT and Plasma GSN Levels with the Prognosis of Urosepsis Patients. Pak J Med Sci. 2020;36(5):---------. doi: https://doi.org/10.12669/pjms.36.5.2143 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

scholarly journals Promoting Research Culture at Indus Health Network

2019 ◽  
Vol 36 (ICON-Suppl) ◽  
Author(s):  
Shaukat Ali Jawaid
Keyword(s):  
Open Access ◽  
Original Work ◽  
Research Culture ◽  
Health Network ◽  
Creative Commons ◽  
Special Supplement ◽  
Open Access Article

doi: https://doi.org/10.12669/pjms.36.ICON-Suppl.1861 How to cite this:Jawaid SA. Promoting Research Culture at Indus Health Network. Pak J Med Sci. Special Supplement ICON 2020. 2020;36(1):S2. doi: https://doi.org/10.12669/pjms.36.ICON-Suppl.1861 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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