The Deployment of the Seismometer to Investigate Ice and Ocean Structure (SIIOS) on Gulkana Glacier, Alaska

2020 ◽  
Vol 91 (3) ◽  
pp. 1901-1914
Author(s):  
Angela G. Marusiak ◽  
Nicholas C. Schmerr ◽  
Daniella N. DellaGiustina ◽  
Erin C. Pettit ◽  
Peter H. Dahl ◽  
...  
Keyword(s):  
Aluminum Plate ◽  
Seismic Sources ◽  
Hydrological Structure ◽  
Active Source ◽  
Test Flight ◽  
Aperture Array ◽  
Similarities And Differences ◽  
Source Signals ◽  
Teleseismic Events ◽  
Initial Results

Abstract The Seismometer to Investigate Ice and Ocean Structure (SIIOS) is a NASA-funded analog mission program to test flight-candidate instrumentation on icy-ocean world analog sites. In September 2017, an SIIOS experiment was deployed on Gulkana Glacier. The instrumentation included a Nanometrics Trillium 120 s Posthole seismometer, four Nanometrics Trillium Compact (TC) seismometers, four Mark Products L28 geophones, and five each of Silicon Audio (SiA) 203P-15 and 203P-60 seismometers. The SiA sensors served as our flight-candidate instruments. The instrumentation was arranged in a small (<2  m) aperture array with most sensors deployed in the ice. We also placed five of the SiA seismometers on top of a mock lander to simulate placement on a lander deck. The instrumentation recorded an active-source experiment immediately after deployment and then passively for 13 days. We conducted an active-source experiment using a sledgehammer striking an aluminum plate at 13 locations, with 9–13 shots occurring at each location. During the passive observation, the experiment recorded one large Mw 7.1 event that occurred in Mexico and four other teleseismic events with Mw>6.0. The active- and passive-source signals are being used to constrain the local glacial hydrological structure, environmental seismicity, to develop algorithms to detect and locate seismic sources, and to quantify the similarities and differences in science capabilities between sensors. Initial results indicate the flight-candidate instrumentation performs comparably to the Trillium Posthole up to periods of 3 s, after which the flight-candidate performs more comparably to the TCs.

scholarly journals Grounding zone subglacial properties from calibrated active-source seismic methods

2021 ◽  
Vol 15 (4) ◽  
pp. 1863-1880
Author(s):  
Huw J. Horgan ◽  
Laurine van Haastrecht ◽  
Richard B. Alley ◽  
Sridhar Anandakrishnan ◽  
Lucas H. Beem ◽  
...  
Keyword(s):  
Coefficient Of Determination ◽  
Seismic Sources ◽  
West Antarctica ◽  
Ice Shelf ◽  
Factors Affecting ◽  
Shear Wave Velocities ◽  
Active Source ◽  
Seismic Methods ◽  
Ice Stream ◽  
Water Layers

Abstract. The grounding zone of Whillans Ice Stream, West Antarctica, exhibits an abrupt transition in basal properties from the grounded ice to the ocean cavity over distances of less than 0.5–1 km. Active-source seismic methods reveal the downglacier-most grounded portion of the ice stream is underlain by a relatively stiff substrate (relatively high shear wave velocities of 1100±430 m s−1) compared to the deformable till found elsewhere beneath the ice stream. Changes in basal reflectivity in our study area cannot be explained by the stage of the tide. Several kilometres upstream of the grounding zone, layers of subglacial water are detected, as are regions that appear to be water layers but are less than the thickness resolvable by our technique. The presence of stiff subglacial sediment and thin water layers upstream of the grounding zone supports previous studies that have proposed the dewatering of sediment within the grounding zone and the trapping of subglacial water upstream of the ocean cavity. The setting enables calibration of our methodology using returns from the floating ice shelf. This allows a comparison of different techniques used to estimate the sizes of the seismic sources, a constraint essential for the accurate recovery of subglacial properties. We find a strong correlation (coefficient of determination=0.46) between our calibrated method and a commonly used multiple-bounce method, but our results also highlight the incomplete knowledge of other factors affecting the amplitude of seismic sources and reflections in the cryosphere.

scholarly journals Grounding zone subglacial properties from calibrated active source seismic methods

2020 ◽  
Author(s):  
Huw J. Horgan ◽  
Laurine van Haastrecht ◽  
Richard B. Alley ◽  
Sridhar Anandakrishnan ◽  
Knut Christianson ◽  
...  
Keyword(s):  
Amplitude Ratio ◽  
Coefficient Of Determination ◽  
Ratio Method ◽  
Seismic Sources ◽  
Factors Affecting ◽  
Shear Wave Velocities ◽  
Active Source ◽  
Seismic Methods ◽  
Ice Stream ◽  
Water Layers

Abstract. The grounding zone of Whillans Ice Stream, West Antarctica, exhibits an abrupt transition in basal properties from the grounded ice to the ocean cavity over distances of less than 0.5–1 km. Active source seismic methods reveal the grounded portion of the ice stream is underlain by a relatively stiff substrate (relatively high shear wave velocities) compared to the deformable till found elsewhere beneath the ice stream. Several kilometers upstream of the grounding zone, layers of subglacial water are detected, as are regions that appear to be water layers less than the thickness resolvable by our technique. The presence of stiff subglacial sediment and thin water layers upstream of the grounding zone supports previous studies that have proposed the dewatering of sediment within the grounding zone and the possibility that ocean water is pumped into the subglacial system and upstream. The setting enables calibration of our methodology using returns from the floating ice shelf. This allows a comparison of different techniques used to estimate the sizes of the seismic sources. We find a strong correlation (coefficient of determination = 0.45) between our calibrated method and a commonly used amplitude ratio method, but our results also highlight the incomplete knowledge of other factors affecting the amplitude of seismic sources and reflections in the cryosphere.

A Field Study Method for Soundscape in Railway Stations

2012 ◽  
Vol 518-523 ◽  
pp. 3796-3799
Author(s):  
Qi Meng ◽  
Zheng Wei Zhang ◽  
Yi Ning Wang
Keyword(s):  
Field Study ◽  
Sociological Theory ◽  
Public Spaces ◽  
Railway Stations ◽  
Capital Cities ◽  
Sound Environment ◽  
Similarities And Differences ◽  
Initial Results

Present, railway stations are rather common in every cities, towns and villages. In this study, the field study method of soundscape in railway stations has been developed, aiming at finding out the relationships between users’ evaluation of sound environment and other factors in such spaces, as well as their similarities and differences with other urban public spaces. Based on sociological theory, questionnaires and simpling methods have been designed. Using these methods, soundscape surveys and measurement have been carried out in 4 railway stations in capital cities, China, considering both staffs and passengers. By analysing the data, some initial results are given in this paper for further research.

Allocentric and Egocentric Controllers: Similarities and Differences

Leonardo ◽  
2021 ◽  
pp. 1-8
Author(s):  
Lilac Atassi
Keyword(s):  
Reference Frame ◽  
Large Degree ◽  
The Body ◽  
Subjective Experiment ◽  
Stationary Reference Frame ◽  
The Subject ◽  
Similarities And Differences ◽  
Level 1 ◽  
High Level ◽  
Initial Results

Abstract Gestural instruments can be divided into two categories based on the type of the reference frame used by the controller. An egocentric controller uses a reference frame that is centered on and follows a point of the performer's body to measure the body point positions relative to some other body points. An allocentric controller uses a stationary reference frame attached to an object other than the performer's body. The allocentric option is the more commonly used by gestural instrument designers. The egocentric option has been used and explored less frequently. This paper studies, at a low level and high level: 1- The similarities and differences between egocentric and allocentric controllers for gestural instruments from the perspective of performer and instrument designer. 2- The affordances and constraints of egocentric and allocentric controllers as they, to a large degree, define the characteristics of an instrument. The paper presents the initial results of a subjective experiment to encourage the future discussion and study of the subject.

scholarly journals Az észlelt kultúraszemélyiség és hatása az ország turisztikai és üzleti célpontként való megítélésére (Investigation the effect of perceived culture – personality (CP) on the evaluation of the country as ideal business/tourist destination)

2014 ◽  
pp. 2-13
Author(s):  
Erzsébet Malota ◽  
Tamás Gyulavári
Keyword(s):  
Scale Development ◽  
Semantic Differential ◽  
Qualitative Studies ◽  
Semantic Differential Scale ◽  
Scale Construction ◽  
Tourist Destination ◽  
Construction Procedure ◽  
Similarities And Differences ◽  
Initial Results

A kutatás fő célja annak vizsgálata, hogy egy adott kultúra észlelt személyisége milyen hatással van az ország ideális turisztikai, illetve üzleti célországként való megítélésére. A kultúraszemélyiség koncepciójának bemutatása után a kultúraszemélyiség-skála (culture personality, CP) fejlesztésének kezdeti eredményeit, majd a kultúraszemélyiség dimenzióinak vizsgálatát részletezik a szerzők. A skálakialakítás során – kvalitatív eredményeiket felhasználva – egy ötvenegy tulajdonságpárból álló szemantikus differenciálskálát fejlesztettek ki és teszteltek. Jelen cikkükben összehasonlítják Franciaország és Magyarország észlelt kultúraszemélyiségét, vizsgálva a magyar és a francia válaszadók véleményének hasonlóságait és különbségeit. Eredményeik azt mutatják, hogy nemcsak az egyes kultúrák személyiségét észlelik eltérően a válaszadók, de ugyanazon kultúra személyiségének bizonyos jellemzőit is eltérően ítélik meg. _____ The main purpose of our study was to investigate the effect of perceived culture – personality (CP) on the evaluation of the country as ideal business/tourist destination. After introducing the concept of culture-personality, initial results of our CP scale development are discussed, and dimensions of culture-personality will be examined. As a result of the scale construction procedure – based on our extensive qualitative studies –, a 51-item semantic differential scale has been developed and tested. Similarities and differences of perceived culture-personalities of France and Hungary among Hungarian and French respondents are described.

Electron Probe Analysis of Vertebrate Smooth Muscle: Distribution of Ca and Ci

1976 ◽  
Vol 34 ◽  
pp. 334-335 ◽  
Author(s):  
Avril V. Somlyo ◽  
H. Shuman ◽  
A.P. Somlyo
Keyword(s):  
Smooth Muscle ◽  
Electron Probe ◽  
Preliminary Report ◽  
Cell Damage ◽  
Electron Probe Analysis ◽  
Perinuclear Space ◽  
Probe Analysis ◽  
High K ◽  
Low K ◽  
Initial Results

This is a preliminary report of electron probe analysis of rabbit portal-anterior mesenteric vein (PAMV) smooth muscle cryosectioned without fixation or cryoprotection. The instrumentation and method of electron probe quantitation used (1) and our initial results with cardiac (2) and skeletal (3) muscle have been presented elsewhere.In preparations depolarized with high K (K2SO4) solution, significant calcium peaks were detected over the sarcoplasmic reticulum (Fig 1 and 2) and the continuous perinuclear space. In some of the fibers there were also significant (up to 200 mM/kg dry wt) calcium peaks over the mitochondria. However, in smooth muscle that was not depolarized, high mitochondrial Ca was found in fibers that also contained elevated Na and low K (Fig 3). Therefore, the possibility that these Ca-loaded mitochondria are indicative of cell damage remains to be ruled out.

Orosensory Perception, Speech Production, and Deafness

1973 ◽  
Vol 16 (2) ◽  
pp. 257-266 ◽  
Author(s):  
Milo E. Bishop ◽  
Robert L. Ringel ◽  
Arthur S. House
Keyword(s):  
High School ◽  
Speech Production ◽  
Poor Performance ◽  
Normal Hearing ◽  
The Other ◽  
Functional Disorders ◽  
Form Discrimination ◽  
School Subjects ◽  
Oral Form ◽  
Similarities And Differences

The oral form-discrimination abilities of 18 orally educated and oriented deaf high school subjects were determined and compared to those of manually educated and oriented deaf subjects and normal-hearing subjects. The similarities and differences among the responses of the three groups were discussed and then compared to responses elicited from subjects with functional disorders of articulation. In general, the discrimination scores separated the manual deaf from the other two groups, particularly when differences in form shapes were involved in the test. The implications of the results for theories relating orosensory-discrimination abilities are discussed. It is postulated that, while a failure in oroperceptual functioning may lead to disorders of articulation, a failure to use the oral mechanism for speech activities, even in persons with normal orosensory capabilities, may result in poor performance on oroperceptual tasks.

High resolution two-dimensional motility mapping; Methodology and initial results

2001 ◽  
Vol 120 (5) ◽  
pp. A226-A226 ◽  
Author(s):  
W LAMMERS ◽  
S DHANASEKARAN ◽  
J SLACK ◽  
B STEPHEN
Keyword(s):  
High Resolution ◽  
Two Dimensional ◽  
Initial Results
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