39 results on '"Brisbourne, Alex"'
Search Results
2. Array processing in cryoseismology: a comparison to network-based approaches at an Antarctic ice stream.
- Author
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Hudson, Thomas Samuel, Brisbourne, Alex M., Kufner, Sofia-Katerina, Kendall, J.-Michael, and Smith, Andy M.
- Subjects
- *
ANTARCTIC ice , *ICE streams , *ICE calving , *ARRAY processing , *ICE sheets , *GLACIERS , *ICE shelves , *SUBGLACIAL lakes - Abstract
Seismicity at glaciers, ice sheets, and ice shelves provides observational constraint on a number of glaciological processes. Detecting and locating this seismicity, specifically icequakes, is a necessary first step in studying processes such as basal slip, crevassing, imaging ice fabric, and iceberg calving, for example. Most glacier deployments to date use conventional seismic networks, comprised of seismometers distributed over the entire area of interest. However, smaller-aperture seismic arrays can also be used, which are typically sensitive to seismicity distal from the array footprint and require a smaller number of instruments. Here, we investigate the potential of arrays and array-processing methods to detect and locate subsurface microseismicity at glaciers, benchmarking performance against conventional seismic-network-based methods for an example at an Antarctic ice stream. We also provide an array-processing recipe for body-wave cryoseismology applications. Results from an array and a network deployed at Rutford Ice Stream, Antarctica, show that arrays and networks both have strengths and weaknesses. Arrays can detect icequakes from further distances, whereas networks outperform arrays in more comprehensive studies of a particular process due to greater hypocentral constraint within the network extent. We also gain new insights into seismic behaviour at the Rutford Ice Stream. The array detects basal icequakes in what was previously interpreted to be an aseismic region of the bed, as well as new icequake observations downstream and at the ice stream shear margins, where it would be challenging to deploy instruments. Finally, we make some practical recommendations for future array deployments at glaciers. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. Characterising ice slabs in firn using seismic full waveform inversion, a sensitivity study.
- Author
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Pearce, Emma, Booth, Adam D., Rost, Sebastian, Sava, Paul, Konuk, Tuğrul, Brisbourne, Alex, Hubbard, Bryn, and Jones, Ian
- Subjects
SEISMIC wave velocity ,ICE ,SEISMIC surveys ,ICE shelves ,ATMOSPHERIC models ,HYDROLOGIC models - Abstract
The density structure of firn has implications for hydrological and climate modelling, and ice-shelf stability. The structure of firn can be evaluated from depth models of seismic velocity, widely obtained with Herglotz–Wiechert inversion (HWI), an approach that considers the slowness of refracted seismic arrivals. However, HWI is strictly appropriate only for steady-state firn profiles and the inversion accuracy can be compromised where firn contains ice layers. In these cases, full waveform inversion (FWI) may yield more success than HWI. FWI extends HWI capabilities by considering the full seismic waveform and incorporates reflected arrivals. Using synthetic firn density profiles, assuming both steady- and non-steady-state accumulation, we show that FWI outperforms HWI for detecting ice slab boundaries (5–80 m thick, 5–80 m deep) and velocity anomalies within firn. FWI can detect slabs thicker than one wavelength (here, 20 m, assuming a maximum frequency of 60 Hz) but requires the starting velocity model to be accurate to ±2.5%. We recommend for field practice that the shallowest layers of velocity models are constrained with ground-truth data. Nonetheless, FWI shows advantages over established methods, and should be considered when the characterisation of firn ice slabs is the goal of the seismic survey. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
4. A synthetic study of acoustic full waveform inversion to improve seismic modelling of firn.
- Author
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Pearce, Emma, Booth, Adam D., Rost, Sebastian, Sava, Paul, Konuk, Tuğrul, Brisbourne, Alex, Hubbard, Bryn, and Jones, Ian
- Subjects
SEISMIC wave velocity ,ICE shelves ,SURFACE waves (Seismic waves) ,SEISMIC waves ,HYDROLOGIC models ,ATMOSPHERIC models ,VELOCITY - Abstract
The density structure of firn has implications for hydrological and climate modelling and for ice shelf stability. The firn structure can be evaluated from depth models of seismic velocity, widely obtained with Herglotz-Wiechert inversion (HWI), an approach that considers the slowness of refracted seismic arrivals. However, HWI is appropriate only for steady-state firn profiles and the inversion accuracy can be compromised where firn contains ice layers. In these cases, Full Waveform Inversion (FWI) can be more successful than HWI. FWI extends HWI capabilities by considering the full seismic waveform and incorporates reflected arrivals, thus offering a more accurate estimate of a velocity profile. We show the FWI characterisation of the velocity model has an error of only 1.7% for regions (vs. 4.2% with HWI) with an ice slab (20 m thick, 40 m deep) in an otherwise steady-state firn profile. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
5. Array processing in cryoseismology.
- Author
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Hudson, Thomas Samuel, Brisbourne, Alex M., Kufner, Sofia-Katerina, Kendall, J.-Michael, and Smith, Andy M.
- Subjects
ARRAY processing ,ICE shelves ,ICE sheets ,ICE streams ,SEISMIC arrays ,SEISMOMETERS ,GLACIOLOGY ,GLACIERS - Abstract
Seismicity at glaciers, ice sheets and ice shelves provides observational constraint of a number of glaciological processes. Detecting and locating this seismicity, specifically icequakes, is a necessary first step in studying processes such as basal slip, crevassing, and imaging ice fabric, for example. Most glacier deployments to date use conventional seismic networks, comprised of seismometers distributed over the entire area of interest. However, smaller aperture seismic arrays can also be used, which are typically sensitive to seismicity distal from the array footprint and require a smaller number of instruments. Here, we investigate the potential of arrays and array-processing methods to detect and locate seismicity in the cryosphere, benchmarking performance against conventional seismic network-based methods. We also provide an array-processing recipe for cryosphere applications. Results from an array and network deployed at Rutford Ice Stream, Antarctica, show that arrays and networks both have strengths and weaknesses. Arrays can detect icequakes from further distances whereas networks outperform arrays for more comprehensive studies of a process within the network extent, due to greater hypocentral constraint and a smaller magnitude of completeness. We also gain new insights into seismic behaviour at Rutford Ice Stream. The array detects basal icequakes in what was previously interpreted to be an aseismic region of the bed, as well as new icequake observations at the ice stream shear-margins, where it would be challenging to deploy instruments. Finally, we make some practical recommendations for future array deployments at glaciers. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
6. Seismic Noise Interferometry and Distributed Acoustic Sensing (DAS): Inverting for the Firn Layer S‐Velocity Structure on Rutford Ice Stream, Antarctica.
- Author
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Zhou, Wen, Butcher, Antony, Brisbourne, Alex M., Kufner, Sofia‐Katerina, Kendall, J‐Michael, and Stork, Anna L.
- Subjects
SURFACE waves (Seismic waves) ,ICE streams ,SEISMIC waves ,INTERFEROMETRY ,MICROSEISMS ,FIBER optic cables ,RAYLEIGH waves ,SEISMIC anisotropy - Abstract
Firn densification profiles are an important parameter for ice‐sheet mass balance and palaeoclimate studies. One conventional method of investigating firn profiles is using seismic refraction surveys, but these are difficult to upscale to large‐area measurements. Distributed acoustic sensing (DAS) presents an opportunity for large‐scale seismic measurements of firn with dense spatial sampling and easy deployment, especially when seismic noise is used. We study the feasibility of seismic noise interferometry (SI) on DAS data for characterizing the firn layer at the Rutford Ice Stream, West Antarctica. Dominant seismic energy appears to come from anthropogenic noise and shear‐margin crevasses. The DAS cross‐correlation interferometry yields noisy Rayleigh wave signals. To overcome this, we present two strategies for cross‐correlations: (a) hybrid instruments—correlating a geophone with DAS, and (b) stacking of selected cross‐correlation panels picked in the tau‐p domain. These approaches are validated with results derived from an active survey. Using the retrieved Rayleigh wave dispersion curve, we inverted for a high‐resolution 1D S‐wave velocity profile down to a depth of 100 m. The profile shows a "kink" (velocity gradient inflection) at ∼12 m depth, resulting from a change of compaction mechanism. A triangular DAS array is used to investigate directional variation in velocity, which shows no evident variations thus suggesting a lack of azimuthal anisotropy in the firn. Our results demonstrate the potential of using DAS and SI to image the near‐surface and present a new approach to derive S‐velocity profiles from surface wave inversion in firn studies. Plain Language Summary: The density distribution (density change with depth) over tens of meters at the top of a glacier is an important feature of ice‐sheet mass balance and palaeoclimate research. It can be estimated using the empirical relationship between density and seismic P‐wave velocity. The P‐wave velocity can be measured using a seismic refraction survey with geophones and active sources. However, refraction seismic surveys are expensive for measurements over large areas. Distributed Acoustic Sensing (DAS) using fiber optic cables to detect seismic waves is an emerging dense spatial sampling seismic acquisition technology. It can be used in conjunction with seismic noise cross‐correlation to make large‐scale measurements easier and cheaper than with conventional geophones. We investigate the feasibility of this approach on Rutford Ice Stream, West Antarctica, and propose two approaches to improve DAS seismic‐noise cross‐correlation results. Surface waves are retrieved by seismic noise cross‐correlation and are used to estimate the S‐wave velocity structure. Our S‐velocity profile resembles an independently measured P‐velocity in‐shape and presents a velocity gradient inflection—related to changes in the snow compaction mechanism. We show that DAS and seismic noise interferometry can be used for future firn measurements, but also more generally in studies of the near‐surface. Key Points: Distributed acoustic sensing (DAS) is used for the first time to derive the S‐wave velocity structure and anisotropy of the firn layer in AntarcticaDAS seismic interferograms are greatly improved through selective stacking and cross‐correlation with a geophoneOur method is suitable for large‐scale measurements and is feasible in the presence of ice lenses where refraction methods are inadequate [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
7. A synthetic study of acoustic full waveform inversion to improve seismic modelling of firn.
- Author
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Pearce, Emma, Booth, Adam D., Rost, Sebastian, Sava, Paul, Konuk, Tuğrul, Brisbourne, Alex, Hubbard, Bryn, and Jones, Ian
- Subjects
SEISMIC wave velocity ,ICE shelves ,SURFACE waves (Seismic waves) ,SEISMIC waves ,HYDROLOGIC models ,ATMOSPHERIC models ,VELOCITY - Abstract
The density structure of firn has implications for hydrological and climate modelling and for ice shelf stability. The firn structure can be evaluated from depth models of seismic velocity, widely obtained with Herglotz-Wiechert inversion (HWI), an approach that considers the slowness of refracted seismic arrivals. However, HWI is appropriate only for steady-state firn profiles and the inversion accuracy can be compromised where firn contains ice layers. In these cases, Full Waveform Inversion (FWI) can be more successful than HWI. FWI extends HWI capabilities by considering the full seismic waveform and incorporates reflected arrivals, thus offering a more accurate estimate of a velocity profile. We show the FWI characterisation of the velocity model has an error of only 1.7% for regions (vs. 4.2% with HWI) with an ice slab (20 m thick, 40 m deep) in an otherwise steady-state firn profile. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
8. Diverse landscapes beneath Pine Island Glacier influence ice flow
- Author
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Bingham, Robert G., Vaughan, David G., King, Edward C., Davies, Damon, Cornford, Stephen L., Smith, Andrew M., Arthern, Robert J., Brisbourne, Alex M., De Rydt, Jan, Graham, Alastair G. C., Spagnolo, Matteo, Marsh, Oliver J., and Shean, David E.
- Subjects
Science ,lcsh:Q ,lcsh:Science ,Article - Abstract
The retreating Pine Island Glacier (PIG), West Antarctica, presently contributes ~5–10% of global sea-level rise. PIG’s retreat rate has increased in recent decades with associated thinning migrating upstream into tributaries feeding the main glacier trunk. To project future change requires modelling that includes robust parameterisation of basal traction, the resistance to ice flow at the bed. However, most ice-sheet models estimate basal traction from satellite-derived surface velocity, without a priori knowledge of the key processes from which it is derived, namely friction at the ice-bed interface and form drag, and the resistance to ice flow that arises as ice deforms to negotiate bed topography. Here, we present high-resolution maps, acquired using ice-penetrating radar, of the bed topography across parts of PIG. Contrary to lower-resolution data currently used for ice-sheet models, these data show a contrasting topography across the ice-bed interface. We show that these diverse subglacial landscapes have an impact on ice flow, and present a challenge for modelling ice-sheet evolution and projecting global sea-level rise from ice-sheet loss., Projecting the future retreat and thus global sea level contributions of Antarctica’s Pine Island Glacier is hampered by a poor grasp of what controls flow at the ice base. Here, via high-resolution ice-radar imaging, the authors show diverse landscapes beneath the glacier fundamentally influence ice flow.
- Published
- 2017
9. Sensitivity of Melting, Freezing and Marine Ice Beneath Larsen C Ice Shelf to Changes in Ocean Forcing.
- Author
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Harrison, Lianne C., Holland, Paul R., Heywood, Karen J., Nicholls, Keith W., and Brisbourne, Alex M.
- Subjects
SEA ice ,ICE ,OCEAN ,ICE shelves ,MELTING ,SEISMIC surveys - Abstract
Observations of surface lowering on Larsen C Ice Shelf (LCIS), Antarctica, have prompted concern about its stability. In this study, an ocean model is used to investigate the extent to which changes in ocean forcing may have influenced ice loss and the distribution of stabilizing marine ice beneath LCIS. The model uses a new bathymetry, containing a southern seabed trough discovered using seismic observations. The modeled extent of marine ice, thought to stabilize LCIS, is in good agreement with observations. Experiments applying idealized ocean warming yield an increase in melting over the southern trough. This is inconsistent with lowering observed in northern LCIS, suggesting oceanic forcing is not responsible for that signal. The marine ice extent and thickness reduces significantly under ocean warming, implying a high sensitivity of LCIS stability to changes in ocean forcing. This result could have wide implications for other cold‐water ice shelves around Antarctica. Plain Language Summary: Satellite observations have revealed a lowering in recent decades of the surface of Larsen C Ice Shelf (LCIS), Antarctica, which has led to concern about its stability. By modeling ocean conditions under LCIS, we investigate the extent to which ocean melting may have caused the ice to thin, leading to the observed lowering, or altered the pattern of marine ice beneath LCIS. Marine ice forms when seawater freezes to the base of the ice shelf, and is thought to stabilize LCIS. The model uses a new seabed data set that contains a wide, deep seabed trough in the south, found by a seismic survey. In modeled ocean warming experiments, an increase in melting is concentrated in this southern region. However, greater lowering has been observed in the north, suggesting that changes in ocean conditions are not responsible for the lowering. The calculated pattern of marine ice at the base of LCIS looks similar to the observed pattern. With a warmer ocean, marine ice is significantly reduced in crucial regions of the ice shelf. This shows that the stability of LCIS is sensitive to changes in ocean conditions and other ice shelves around Antarctica are likely sensitive to these changes too. Key Points: An ocean model with new Larsen C bathymetry shows greatest melting and melt sensitivity where seismic data indicate a deep southern troughThe calculated marine ice distribution under Larsen C Ice Shelf, based on model melt/freeze rates, is in good agreement with observationsA reduction in marine ice with ocean warming implies a threat to Larsen C stability, with wide implications for cold‐water ice shelves [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
10. Radar Derived Subglacial Properties and Landforms Beneath Rutford Ice Stream, West Antarctica.
- Author
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Schlegel, Rebecca, Murray, Tavi, Smith, Andrew M., Brisbourne, Alex M., Booth, Adam D., King, Edward C., and Clark, Roger A.
- Subjects
LANDFORMS ,ICE streams ,SEDIMENT analysis ,DEFORMATIONS (Mechanics) ,POROSITY - Abstract
Basal properties beneath ice streams and glaciers are known to be a control for ice flow dynamics, hence knowledge of them is crucial for predicting sea level due to changes in glacial dynamics. Basal properties, processes and topography also drive the formation of subglacial landforms. Bed properties beneath Rutford Ice Stream (West Antarctica) have previously been described using seismic acoustic impedance measurements at a sparse spatial coverage. Here, we derive bed properties in a 15 × 17 km grid of surface radar data with coverage and sampling much higher than previous seismic studies. Bed reflection amplitudes in surface radar data were calibrated using sediment porosities (ranging from 0.4–0.5) derived from seismic acoustic impedance. We find the bed properties are spatially variable, consisting of low porosity material in some areas and soft sediment in other areas. Comparison of seismic and surface radar data imply the low porosity material to be a consolidated sediment or sedimentary rock. Mega‐scale glacial lineations (MSGLs) are ubiquitous on the bed and consist of soft, high porosity, probably deforming sediment, consistent with previous interpretations of MSGLs. We find some MSGLs have high reflectivity on their crest, interpreted as water bodies overlying high porosity sediment, whereas the trough around and the upstream end of some landforms consist of low porosity material. Integrating these different observations, we place constraints on possible explanations for the occurrence of water on the crest of landforms. Plain Language Summary: Physical properties of rocks and sediments as well as the presence of water beneath ice streams and glaciers control the flow of the ice. Understanding glacial flow is important to better constrain predictions of sea‐level changes. Within this study we present physical properties of material beneath Rutford Ice Stream in West Antarctica over a 15 × 17 km area. Our data show areas of high porosity interpreted as wet sediment and areas of low porosity beneath the ∼2 km thick ice stream. Ice movement above areas of soft sediment is assumed to be maintained by sediment deformation, whereas in areas overlain by low porosity material, sliding of the ice over this material is assumed to maintain flow. The topography beneath Rutford Ice Stream shows many elongated landforms, some over 14 km long. We show that these landforms partly consist of soft sediment. Some of these seem to have a water layer on their crest, but it is not well understood why. However, there might be variations in the sediment composition of the landforms enabling the creation of this water layer. The occurrence of materials with different properties and water show us how heterogenous the bed beneath ice streams can be, which is important for modeling ice stream motion. Key Points: Glacier bed properties (water content, porosity) are constrained using surface radar data calibrated with seismic acoustic impedanceResults show sequences of low porosity material (consolidated sediment or rock), soft sediment and free‐water beneath Rutford Ice StreamMega‐scale glacial lineations are pervasive beneath ice streams, some with a free water layer >10 km long and 100 m wide along their crest [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
11. Non-contact measurement system for hot water drilled ice boreholes.
- Author
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McAfee, Carson W. I., Rix, Julius, Quirk, Sean J., Anker, Paul G. D., Brisbourne, Alex M., and Makinson, Keith
- Subjects
ICE cores ,BOREHOLES ,SUBGLACIAL lakes ,REMOTE sensing ,DATA analysis - Abstract
A programmable borehole measurement system was deployed in hot water drilled ice holes during the 'Bed Access and Monitoring of Ice Sheet History' (BEAMISH) project to drill to the bed of the Rutford Ice Stream in West Antarctica. This system operates autonomously (no live data) after deployment, and records borehole diameter (non-contact measurement), water column pressure, heading and inclination. Three cameras, two sideways looking and one vertical, are also included for visual inspection of hole integrity and sediments. The system is small, lightweight (~35.5 kg) and low power using only 6 'D' cell sized lithium batteries, making it ideal for transport and use in remote field sites. The system is 2.81 m long and 165 mm in diameter, and can be deployed attached to the drill hose for measurements during drilling or on its own deployment line afterwards. The full system is discussed in detail, highlighting design strengths and weaknesses. Data from the BEAMISH project are also presented in the form of camera images showing hole integrity, and sensor data used to calculate borehole diameter through the full length of the hole. These data are used to show confidence in hole verticality and subsurface cavity development and connection. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
12. Downhole distributed acoustic seismic profiling at Skytrain Ice Rise, West Antarctica.
- Author
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Brisbourne, Alex M., Kendall, Michael, Kufner, Sofia-Katerina, Hudson, Thomas S., and Smith, Andrew M.
- Subjects
- *
VERTICAL seismic profiling , *ICE sheets , *ICE , *ANTARCTIC ice , *SEISMIC wave velocity - Abstract
Antarctic ice sheet history is imprinted in the structure and fabric of the ice column. At ice rises, the signature of ice flow history is preserved due to the low strain rates inherent at these independent ice flow centres. We present results from a distributed acoustic sensing (DAS) experiment at Skytrain Ice Rise in the Weddell Sea sector of West Antarctica, aimed at delineating the englacial fabric to improve our understanding of ice sheet history in the region. This pilot experiment demonstrates the feasibility of an innovative technique to delineate ice rise structure. Both direct and reflected P- and S-wave energy, as well as surface wave energy, are observed using a range of source offsets, i.e. a walkaway vertical seismic profile, recorded using fibre optic cable. Significant noise, which results from the cable hanging untethered in the borehole, is modelled and suppressed at the processing stage. At greater depth where the cable is suspended in drilling fluid, seismic interval velocities and attenuation are measured. Vertical P-wave velocities are high (VINT=3984±218 m s -1) and consistent with a strong vertical cluster fabric. Seismic attenuation is high (QINT=75±12) and inconsistent with previous observations in ice sheets over this temperature range. The signal level is too low, and the noise level too high, to undertake analysis of englacial fabric variability. However, modelling of P- and S-wave travel times and amplitudes with a range of fabric geometries, combined with these measurements, demonstrates the capacity of the DAS method to discriminate englacial fabric distribution. From this pilot study we make a number of recommendations for future experiments aimed at quantifying englacial fabric to improve our understanding of recent ice sheet history. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
13. Not all Icequakes are Created Equal: Basal Icequakes Suggest Diverse Bed Deformation Mechanisms at Rutford Ice Stream, West Antarctica.
- Author
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Kufner, Sofia‐Katerina, Brisbourne, Alex M., Smith, Andrew M., Hudson, Thomas S., Murray, Tavi, Schlegel, Rebecca, Kendall, John M., Anandakrishnan, Sridhar, and Lee, Ian
- Subjects
DEFORMATION of surfaces ,GLACIAL melting ,MICROSEISMS ,VELOCITY - Abstract
Microseismicity, induced by the sliding of a glacier over its bed, can be used to characterize frictional properties of the ice‐bed interface, which are a key parameter controlling ice stream flow. We use naturally occurring seismicity to monitor spatiotemporally varying bed properties at Rutford Ice Stream, West Antarctica. We locate 230,000 micro‐earthquakes with local magnitudes from −2.0 to −0.3 using 90 days of recordings from a 35‐station seismic network located ∼40 km upstream of the grounding line. Events exclusively occur near the ice‐bed interface and indicate predominantly flow‐parallel stick‐slip. They mostly lie within a region of interpreted stiff till and along the likely stiffer part of mega‐scale glacial lineations. Within these regions, micro‐earthquakes occur in spatially (<100 m radius) and temporally (mostly 1–5 days activity) restricted event‐clusters (up to 4,000 events), which exhibit an increase, followed by a decrease, in event magnitude with time. This may indicate event triggering once activity is initiated. Although ocean tides modulate the surface ice flow velocity, we observe little periodic variation in overall event frequency over time and conclude that water content, bed topography and stiffness are the major factors controlling microseismicity. Based on variable rupture mechanisms and spatiotemporal characteristics, we suggest the event‐clusters relate to three end‐member types of bed deformation: (1) continuous creation and seismogenic destruction of small‐scale bed‐roughness, (2) ploughed clasts, and (3) flow‐oblique deformation during landform formation or along bedrock outcrops. This indicates that multiple processes, simultaneously active during glacial sliding, can accommodate stick‐slip behavior and that the bed continuously reorganizes. Key Points: We locate 230,000 micro‐earthquakes, with rupture mechanisms, at the base of a fast‐flowing West Antarctic ice stream within a 3‐month periodEvent distribution is little affected by tidal modulations and indicates basal sliding most affected by bed topography, stiffness, and fluidsEvents occur clustered, likely due to different types of bed deformation: mobile asperities, ploughed clasts and flow‐oblique bed features [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
14. Subglacial lakes and hydrology across the Ellsworth Subglacial Highlands, West Antarctica.
- Author
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Napoleoni, Felipe, Jamieson, Stewart S. R., Ross, Neil, Bentley, Michael J., Rivera, Andrés, Smith, Andrew M., Siegert, Martin J., Paxman, Guy J. G., Gacitúa, Guisella, Uribe, José A., Zamora, Rodrigo, Brisbourne, Alex M., and Vaughan, David G.
- Subjects
SUBGLACIAL lakes ,LAKE hydrology ,DRUMLINS ,WATERSHEDS ,ICE streams ,ICE sheets ,DIGITAL elevation models - Abstract
Subglacial water plays an important role in ice sheet dynamics and stability. Subglacial lakes are often located at the onset of ice streams and have been hypothesised to enhance ice flow downstream by lubricating the ice–bed interface. The most recent subglacial-lake inventory of Antarctica mapped nearly 400 lakes, of which ∼ 14 % are found in West Antarctica. Despite the potential importance of subglacial water for ice dynamics, there is a lack of detailed subglacial-water characterisation in West Antarctica. Using radio-echo sounding data, we analyse the ice–bed interface to detect subglacial lakes. We report 33 previously uncharted subglacial lakes and present a systematic analysis of their physical properties. This represents a ∼ 40 % increase in subglacial lakes in West Antarctica. Additionally, a new digital elevation model of basal topography of the Ellsworth Subglacial Highlands was built and used to create a hydropotential model to simulate the subglacial hydrological network. This allows us to characterise basal hydrology, determine subglacial water catchments and assess their connectivity. We show that the simulated subglacial hydrological catchments of the Rutford Ice Stream, Pine Island Glacier and Thwaites Glacier do not correspond to their ice surface catchments. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
15. An updated seabed bathymetry beneath Larsen C Ice Shelf, Antarctic Peninsula.
- Author
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Brisbourne, Alex, Kulessa, Bernd, Hudson, Thomas, Harrison, Lianne, Holland, Paul, Luckman, Adrian, Bevan, Suzanne, Ashmore, David, Hubbard, Bryn, Pearce, Emma, White, James, Booth, Adam, Nicholls, Keith, and Smith, Andrew
- Subjects
- *
ICE shelves , *OCEAN bottom , *BATHYMETRY , *OCEAN circulation , *PENINSULAS , *THICKNESS measurement - Abstract
In recent decades, rapid ice shelf disintegration along the Antarctic Peninsula has had a global impact through enhancing outlet glacier flow and hence sea level rise and the freshening of Antarctic Bottom Water. Ice shelf thinning due to basal melting results from the circulation of relatively warm water in the underlying ocean cavity. However, the effect of sub-shelf circulation on future ice shelf stability cannot be predicted accurately with computer simulations if the geometry of the ice shelf cavity is unknown. To address this deficit for Larsen C Ice Shelf, West Antarctica, we integrate new water column thickness measurements from recent seismic campaigns with existing observations. We present these new data here along with an updated bathymetry grid of the ocean cavity. Key findings include a relatively deep seabed to the southeast of the Kenyon Peninsula, along the grounding line and around the key ice shelf pinning-point of Bawden Ice Rise. In addition, we can confirm that the cavity's southern trough stretches from Mobiloil Inlet to the open ocean. These areas of deep seabed will influence ocean circulation and tidal mixing and will therefore affect the basal-melt distribution. These results will help constrain models of ice shelf cavity circulation with the aim of improving our understanding of sub-shelf processes and their potential influence on ice shelf stability. The datasets are comprised of all the new point measurements of seabed depth. We present the new depth measurements here, as well as a compilation of previously published measurements. To demonstrate the improvements to the sub-shelf bathymetry map that these new data provide we include a gridded data product in the Supplement of this paper, derived using the additional measurements of both offshore seabed depth and the thickness of grounded ice. The underlying seismic datasets that were used to determine bed depth and ice thickness are available at 10.5285/315740B1-A7B9-4CF0-9521-86F046E33E9A (Brisbourne et al., 2019), 10.5285/5D63777D-B375-4791-918F-9A5527093298 (Booth, 2019), 10.5285/FFF8AFEE-4978-495E-9210-120872983A8D (Kulessa and Bevan, 2019) and 10.5285/147BAF64-B9AF-4A97-8091-26AEC0D3C0BB (Booth et al., 2019). [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
16. An updated seabed bathymetry beneath Larsen C Ice Shelf, west Antarctic.
- Author
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Brisbourne, Alex, Kulessa, Bernd, Hudson, Thomas, Harrison, Lianne, Holland, Paul, Luckman, Adrian, Bevan, Suzanne, Ashmore, David, Hubbard, Bryn, Pearce, Emma, White, James, Booth, Adam, Nichols, Keith, and Smith, Andrew
- Subjects
- *
ICE shelves , *OCEAN bottom , *OCEAN circulation , *BATHYMETRY , *THICKNESS measurement , *SEA level - Abstract
In recent decades, rapid ice-shelf disintegration along the Antarctic Peninsula has had a global impact through enhancing outlet glacier flow, and hence sea level rise, and the freshening of Antarctic Bottom Water. Ice shelf thinning due to basal melting results from the circulation of relatively warm water in the underlying ocean cavity. However, the effect of sub-shelf circulation on future ice-shelf stability cannot be predicted accurately with computer simulations if the geometry of the ice-shelf cavity is unknown. To address this deficit for Larsen C Ice Shelf, west Antarctica, we integrate new water-column thickness measurements with existing observations. We present these new data here along with an updated bathymetry grid of the ocean cavity. Key findings include relatively deep seabed to the south-east of the Kenyon Peninsula, along the grounding line and around the key ice shelf pinning point of Bawden Ice Rise. In addition, we can confirm that the cavity’s southern trough stretches from Mobiloil Inlet to the open ocean. These areas of deep seabed will influence ocean circulation and tidal mixing, and will therefore affect the basal-melt distribution. These results will help constrain models of ice-shelf cavity circulation with the aim of improving our understanding of sub-shelf processes and their potential influence on ice shelf stability. The data set comprises all point measurements of seabed depth and a gridded data product, derived using additional measurements of both offshore seabed depth and the thickness of grounded ice. We present all new depth measurements here as well as a compilation of previously published measurements used in the gridding process. The gridded data product is included in the supplementary material. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
17. Five Tips for Seamless M2M Connectivity Globally
- Author
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Brisbourne, Alex
- Subjects
Telecommunications services industry -- Services -- Market research ,Communications industry -- Services -- Market research ,Marketing research ,Telecommunications services industry ,Telecommunications industry - Abstract
Byline: Alex Brisbourne, COO and President, KORE Telematics Until recently, the M2M market was largely regional, with local M2M services providers and local applications providers. As the market has matured, [...]
- Published
- 2009
18. Rise of the machines
- Author
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Brisbourne, Alex
- Subjects
Machinery -- Reports -- Evaluation -- Forecasts and trends ,Technology -- Reports -- Evaluation -- Forecasts and trends ,Magneto-electric machines -- Reports -- Evaluation -- Forecasts and trends ,Business, general ,Government ,Market trend/market analysis ,Evaluation ,Reports ,Forecasts and trends - Abstract
Byline: Alex Brisbourne Machines that 'talk' to other machines might sound like science fiction, but in fact, private industries and public agencies across the country use millions of machine-to-machine (M2M) [...]
- Published
- 2007
19. How dynamic are ice-stream beds?
- Author
-
Davies, Damon, Bingham, Robert G., King, Edward C., Smith, Andrew M., Brisbourne, Alex M., Spagnolo, Matteo, Graham, Alastair G. C., Hogg, Anna E., and Vaughan, David G.
- Subjects
ICE streams ,ICE caps ,ANTARCTIC glaciers ,SEDIMENT transport - Abstract
Projections of sea-level rise contributions from West Antarctica's dynamically thinning ice streams contain high uncertainty because some of the key processes involved are extremely challenging to observe. An especially poorly observed parameter is sub-decadal stability of ice-stream beds, which may be important for subglacial traction, till continuity and landform development. Only two previous studies have made repeated geophysical measurements of ice-stream beds at the same locations in different years, but both studies were limited in spatial extent. Here, we present the results from repeat radar measurements of the bed of Pine Island Glacier, West Antarctica, conducted 3-6 years apart, along a cumulative ~60 km of profiles. Analysis of the correlation of bed picks between repeat surveys shows that 90% of the bed displays no significant change despite the glacier increasing in speed by up to 40% over the last decade. We attribute the negligible detection of morphological change at the bed of Pine Island Glacier to the ubiquitous presence of a deforming till layer, wherein sediment transport is in steady state, such that sediment is transported along the basal interface without inducing morphological change to the radarsounded basal interface. Given the precision of our measurements, the upper limit of subglacial erosion observed here is 500mma
-1 , far exceeding erosion rates reported for glacial settings from proglacial sediment yields, but substantially below subglacial erosion rates of 1.0ma-1 previously reported from repeat geophysical surveys in West Antarctica. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
20. Ice fabric in an Antarctic ice stream interpreted from seismic anisotropy.
- Author
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Smith, Emma C., Baird, Alan F., Kendall, J. Michael, Martín, Carlos, White, Robert S., Brisbourne, Alex M., and Smith, Andrew M.
- Published
- 2017
- Full Text
- View/download PDF
21. The search for seismic signatures of movement at the glacier bed in a polythermal valley glacier.
- Author
-
POMEROY, Joseph, BRISBOURNE, Alex, EVANS, Jeffrey, and GRAHAM, David
- Subjects
- *
GLACIERS , *VALLEYS , *WAVE analysis , *SEISMIC waves , *GEOPHONE , *SEISMOLOGY - Abstract
A passive seismology experiment was conducted across the main overdeepening of Storglaciaren in the Tarfala valley, northern Sweden, to investigate the spatial and temporal distribution of basal microseismic waveforms in relation to known dynamics of this small polythermal sub-arctic glacier. The high ablation rate made it difficult to keep geophones buried and well coupled to the glacier during the experiment and reduced the number of days of good-quality data collection. The characterization of typical and atypical waveforms showed that the dominant waveforms were from near-surface events such as crevassing. Waveforms resembling basal microseismic signals were very rare, and seldom observed on more than two seismic stations simultaneously. The analysis of waveforms, amplitudes and particle motions suggested a near-field origin for most events. Even though basal sliding is known to occur in the overdeepening, no convincing examples of basal waveforms were detected, suggesting basal microseismic signals are rare or difficult to detect beneath polythermal glaciers like Storglaciaren. We discuss the reasons for failing to locate basal signals, consider the origin of common waveforms and make recommendations for setting up passive seismology experiments on glaciers with high ablation rates. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
22. Anisotropic structure of the Hikurangi subduction zone, New Zealand--integrated interpretation of surface-wave and body-wave observations.
- Author
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Brisbourne, Alex, Stuart, Graham, and Kendall, J. -Michael
- Subjects
- *
ANISOTROPY , *SEISMIC tomography , *SUBDUCTION zones - Abstract
Presents the anisotropic structure of the Hikurangi subduction zone in New Zealand. Assessment of the shear-wave anisotropy of surface-wave polarizations; Elaboration of symmetry axis of the anisotropic structure; Anisotropic characteristics in the subducted crust underlying the mantle.
- Published
- 1999
- Full Text
- View/download PDF
23. Shear-wave velocity structure beneath North Island, New Zealand, from Rayleigh-wave interstation phase velocities.
- Author
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Brisbourne, Alex M. and Stuart, Graham W.
- Subjects
- *
RAYLEIGH waves , *SPEED - Abstract
Investigates Rayleigh-wave dispersion to determine the shear-wave velocity structure in North Island, New Zealand. Implication of surface-wave study for the thickness of the upper-mantle; Use of anisotropy to explain the presence of high velocities; Indication of the result of the mantle velocities from the isotropic inversions of the S-wave velocity.
- Published
- 1998
- Full Text
- View/download PDF
24. New insights into polar ice crystal fabrics from radar polarimetry.
- Author
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Martin, Carlos, Brisbourne, Alex, Kingslake, Jonathan, Mulvaney, Robert, Rix, Julius, Ritz, Catherine, Nicholls, Keith, Drews, Reinhard, Lindback, Katrin, and Matsuoka, Kenichi
- Subjects
- *
GREENLAND ice , *POLARIMETRY , *ICE shelves , *ICE cores , *RADAR , *ICE crystals , *ICE - Abstract
Ice is one of the most anisotropic natural materials but it is common knowledge in our community that anisotropy in ice is: a) a second order factor that can be ignored, b) easily assimilated into isotropic models by tuning certain parameters, or c) so complicated that it is better to ignore. Interestingly, any measurement of anisotropy in polar ice shows that ice develops crystalline preferred-orientation fabrics that produce strong mechanical, optical and dielectric anisotropic properties. Here, we look in detail at polarimetric radar measurements in different regions of East and West Antarctica. We use a ground-based phase-sensitive frequency-modulated continuous-wave radar (ApRES) and a matrix-based model to study the radio-waves depolarization and anisotropic scattering (Fujita et al, 2006). We find that anisotropy is widespread and an excellent archive of past ice flow conditions. We use it here to extract details of the recent deglaciation of the Ross and Ronny ice shelves over the last thousands of years. Also, because the length of the record is related to the advection time of the ice flow, we use our method to show that a candidate ice core location near Dome C, for the Beyond Epica Oldest Ice Core project, has been under steady ice-flow conditions over the last million years or so. [ABSTRACT FROM AUTHOR]
- Published
- 2019
25. Seismic acoustic impedance, effective pressure, and basal drag.
- Author
-
Arthern, Robert, Brisbourne, Alex, Smith, Andrew, and Williams, Rosie
- Subjects
- *
SPEED of sound , *SOUND pressure , *WATER pressure , *SEISMIC surveys , *GRANULAR materials , *ACOUSTIC impedance - Abstract
Acoustic impedance is a measurable quantity that can be recovered using active seismic surveys. Its value depends on the speed of sound in the sediment and the sediment density. For granular sediments there are theories that relate the speed of sound to the effective pressure, the difference between ice overburden and subglacial water pressure. This provides a link between the seismic observable and a key control on basal sliding. For sediments that follow a Coulomb friction law, the higher the effective pressure the higher the shear stress supported by the sediments. In this presentation we investigate the links between acoustic impedance, effective pressure and basal drag that are predicted by theories of the speed of sound in granular materials. We use results for basal drag from an ice flow model inversion in Antarctica to predict how acoustic impedance would vary under the hypothesis that sliding is controlled by a Coulomb sliding law. [ABSTRACT FROM AUTHOR]
- Published
- 2019
26. New insights into polar ice crystal fabrics from radar polarimetry.
- Author
-
Martin, Carlos, Brisbourne, alex, Kingslake, Jonnathan, Mulvaney, Robert, Riz, Julius, Ritz, Catherine, Drews, Reinhard, Lindbäck, Katrin, and Matsuoka, Kenichi
- Subjects
- *
GREENLAND ice , *POLARIMETRY , *RADAR , *ICE crystals , *INSIGHT - Published
- 2018
27. Diverse landscapes beneath Pine Island Glacier influence ice flow.
- Author
-
Bingham, Robert G., Vaughan, David G., King, Edward C., Davies, Damon, Cornford, Stephen L., Smith, Andrew M., Arthern, Robert J., Brisbourne, Alex M., De Rydt, Jan, Graham, Alastair G. C., Spagnolo, Matteo, Marsh, Oliver J., and Shean, David E.
- Published
- 2018
- Full Text
- View/download PDF
28. Mechanical response of Larsen C Ice Shelf following the A68 calving event: observations from field-based geophysical measurements.
- Author
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Booth, Adam, Luckman, Adrian, White, Jim, Pearce, Emma, Cornford, Stephen, Kulessa, Bernd, Brisbourne, Alex, and Hubbard, Bryn
- Published
- 2018
29. Full Waveform Inversion to determine the seismic structure of firn
- Author
-
Pearce, Emma Valerie Eve, Booth, Adam, Rost, Sebastian, Hubbard, Bryn, Brisbourne, Alex, and Jones, Ian
- Abstract
The compaction of firn (the transition of snow to ice) is a process in glaciology that is difficult to constrain without the use of intrusive geophysical techniques. Full Waveform Inversion (FWI) is a seismic imaging technique used to obtain high-resolution images of the subsurface. This research introduces FWI to glaciological modelling and shows that FWI can improve upon the Herglotz-Wiechert travel time tomography method that's use is currently widespread. Using synthetic firn velocity models, acoustic FWI was shown to recover the compressional (P) wave velocity gradient of the firn column and could correct a velocity model that was a poor representation of the subsurface structure (up to a 5% velocity error). Additionally, FWI was able to detect ice layers of a minimum thickness of 10 m (half the minimum wavelength) within the firn column and provide constraints on their depth providing the ice slab did not occur in the shallow surface (20 m or less), where the steepest velocity gradient occurs. FWI is applied to two datasets. Firstly, legacy data acquired by the British Antarctic Survey on Pine Island Glacier were problematic, owing to an inconsistent, high-frequency source waveform that made FWI vulnerable to cycle skipping. Consequently, no improvement was observed to the seismic structure. Secondly, a dataset acquired specifically for this research was collected on Norway's Hardangerjøkulen Ice Cap. With this dataset a combination of Travel Time and Least-Squares FWI can be successful due to the use of a repeatable seismic source with lower frequency content (10 Hz), A VSP survey used to provide near-surface velocity constraints and near offset small receiver spacing (1 m). FWI provided a 6% change to the starting velocity model and improved the data match by 47%. The results showed that acoustic FWI must be considered from the seismic acquisition stage for the technique to be successful in characterising firn velocity structure. In this case, FWI can improve the model of the subsurface velocity structure from the HW technique and increase the match of the modelled seismic data.
- Published
- 2021
30. The tectonic structure and seismicity of West Antarctica from a regional seismic deployment
- Author
-
Dunham, Charles Kingsley, Stuart, Graham, Rost, Sebastian, and Brisbourne, Alex
- Abstract
In this thesis I investigate the tectonic structure and seismicity of West Antarctica using recently deployed seismic networks. To study the crustal thickness of West Antarctica's constituent tectonic blocks, I model crustal shear-wave velocity structure using a joint inversion of receiver functions and Rayleigh wave phase velocity dispersion. I model crustal thickness from 30-38 km in the Antarctic Peninsula, and 38-40 km in the Haag-Ellsworth Whitmore block. Within the West Antarctic Rift System (WARS), I model a crustal thickness range of 18-28 km, and show that the thinnest crust is in the vicinity of the Byrd Subglacial Basin and Bentley Subglacial Trench. I find that the thin WARS crust extends towards the Pine Island Rift, suggesting that the northern boundary of the WARS lies in this region, ~200 km north of its previously accepted position. I additionally forward model high frequency receiver functions to assess if any thick, low velocity subglacial sediment accumulations are present, finding a 0.1-0.8 km thick layer at 10 stations. Such subglacial sediment could provide a source region for the soft basal till that acts to accelerate ice flow. To investigate the active processes occurring in West Antarctica I study local seismicity recorded from 2015-2018. I locate 86 events during this period, of which I categorise 32 as `likely tectonic', 17 as `likely ice-quakes' and 37 as `possible ice-quakes'. The distribution of events correlates well with modelled regions of high uplift resulting from Glacial Isostatic Adjustment. I also investigate styles and patterns of cryoseismicity produced by Pine Island Glacier, recorded at nearby stations from 2016-2018. High frequency (1-5 Hz) tremor produced by iceberg calving was detected at stations >250 km away from the glacier's calving front, whilst smaller repetitive seismicity produced by the destruction of the glacier's ice melange is also located.
- Published
- 2020
31. Going Beyond LBS with Machine-Based Communications.
- Author
-
Brisbourne, Alex
- Subjects
MOBILE communication systems ,GLOBAL Positioning System ,AUTOMATIC vehicle location systems ,TELECOMMUNICATION systems ,WIRELESS communications - Abstract
The article discusses industrial applications of cellular networks that are quietly improving life. An example is General Motor's OnStar service. Through the help of global positioning system (GPS) satellite service, and real-time communication on demand over the cellular network, locating a car to within a few yards is made possible at a price anyone can realistically afford. In other areas, cellular machine communications linked with location capabilities are seeing innovative solutions to logistics services and supply chains.
- Published
- 2008
32. Investigating volcanic and glacial processes using microseismicity
- Author
-
Hudson, Thomas Samuel, Brisbourne, Alex, and White, Robert
- Subjects
551.2 ,seismology ,cryoseismology ,glaciology ,volcano ,glacier ,geophysics ,crevassing ,glacier sliding ,volcano seismology ,earthquake detection ,source mechanism inversion ,sea level rise ,volcanic hazard - Abstract
Volcanoes and glaciers can both pose a significant threat to life and property. Volcanoes can erupt suddenly, without warning, causing injury, death and damage to property. Glaciers generally present a hazard over longer timescales, melting or sliding into the oceans and contributing to sea-level rise. The movement of melt at volcanoes, and ice at and near the Earth's poles, can be investigated using microseismicity, emitted when these fluids and bodies release kinetic energy as they move. I use this microseismicity to study: melt moving from the deep crust and feeding Bardarbunga volcano, Iceland, before and after an eruption; icequakes at the bed of glaciers and ice sheets to study and constrain the physics of glacial sliding; and surface icequakes caused by crevassing, to see whether or not the crevasses observed are induced by hydrofracture. I use a combination of seismic observations and simple physical models to investigate these fundamental geophysical processes. Understanding the magmatic plumbing of a volcano is important for attempting to improve eruption forecasting. I analyse microseismicity before and after the Bardarbunga volcanic eruption, the largest eruption in Iceland in 230 years, to study possible pathways of melt from the deep crust to the shallow melt storage region. The seismicity and earthquake source mechanisms suggest that melt travels along a pathway that is approximately vertical, and laterally offset from the main shallow melt storage region by 12 km. However, it is also likely that an aseismic melt feed exists directly under Bardarbunga that we do not observe. These observations imply that volcanoes can be fed from depth, with lateral offsets of 10s kms, and that it is not adequate to monitor such volcanoes using seismicity alone. One critical process for constraining sea-level rise projections is glacial sliding. I describe how to detect and locate icequakes that originate at the bed of glaciers, which can be used to study glacial sliding. I analyse icequake source mechanisms for several glacial settings, comprising a range of spatial scales, in an attempt to unify the theory of stick-slip icequake failure, what it can tell us about glacial slip, and how such icequakes can be used to provide the first remotely measured values of bed shear modulus. The method used to remotely measure bed shear modulus will help constrain ice dynamics models and inform future passive cryoseismology studies of the Earth's ice sheets. Another poorly understood process is surface crevassing. Again, I analyse the source mechanisms of surface crevassing icequakes and show that they are tensile cracks, opening in the shallow subsurface. I present a novel method of obtaining depth estimates for these crevasse icequakes. Deriving crevasse depth is important since crevasse depth is usually limited by the stress distribution within the ice column, unless they are filled with water that can allow deeper propagation via hydrofracture. This mechanism is a possible pathway of meltwater propagating from surface to bed, lubricating the bed and exacerbating the movement of ice into the ocean. The same mechanism is also important for understanding how ice shelves, such as the Larson B ice shelf, break up, releasing onshore ice to flow unperturbed into the ocean. Such observations of crevasse fracture are therefore of great relevance for understanding key instabilities that could contribute to future sea-level changes. My results help inform our understanding of the aforementioned processes, which are critical for forecasting volcanic eruptions better, and informing and constraining ice dynamics models used for sea-level rise projections.
- Published
- 2019
- Full Text
- View/download PDF
33. UK seismology – 2002 and beyond.
- Author
-
Brisbourne, Alex
- Subjects
- *
SEISMOLOGICAL research , *SEISMOLOGISTS - Abstract
Alex Brisbourne reports on a one-day discussion meeting organized by SEIS-UK for seismologists to discuss current seismological research undertaken in the UK and to consider how the provision of new seismic equipment and training facility may enhance that work. [ABSTRACT FROM AUTHOR]
- Published
- 2002
- Full Text
- View/download PDF
34. Safeguarding the IoT: Putting Security Front and Center.
- Author
-
Brisbourne, Alex
- Subjects
INTERNET of things ,DATA protection ,NETWORK PC (Computer) ,COMPUTER security - Abstract
The article introduces Internet of Things (IoT) and discusses its uses including remote monitoring applications and utility metering and steps to keep our data safe in IoT by understanding data protection, ensuring front and center security and keep track of the access to the data and system.
- Published
- 2015
35. The Use of Machine-to-Machine Communication in Environmental Impact Monitoring.
- Author
-
Brisbourne, Alex
- Subjects
MACHINE-to-machine communications ,WASTEWATER treatment ,AIR quality ,BUSINESS revenue ,AUTOMATION ,CUSTOMER services - Abstract
The article discusses the implementation of machine-to-machine communications in observing the environment which includes floor management, wastewater treatment, and air quality evaluation. The wireless connectivity employed by the technology allows efficiency resulting to increased revenues. The development of its applications and solutions is expected to deliver enhanced processes and automation that will lead to improved customer service, and new offerings.
- Published
- 2013
36. M2M Networks - When You Need Them and Key Considerations for Selecting One.
- Author
-
Brisbourne, Alex
- Subjects
WIRELESS Internet ,WIRELESS communications ,INTERNETWORKING devices ,INTERNETWORKING ,REMOTE control - Abstract
The article discusses the process of selecting the means for wireless Internet Protocol (IP) connectivity. It highlights the eight considerations when choosing a machine-to-machine (M2M) network and provides each step in the M2M network services selection process. These considerations include the one-touch global connectivity and management of wireless resources, specialty rating and billing and the independent redundancy. It suggests investigating all options before choosing an M2M network.
- Published
- 2011
37. It's Time To Ask What Higher Bandwidth Technologies Can Do For You.
- Author
-
Brisbourne, Alex
- Subjects
LONG-Term Evolution (Telecommunications) ,DIGITAL signage - Abstract
The article talks about the application of 3G, 4G, and Long-Term Evolution (LTE) connectivity for new Machine to Machine (M2M) applications and capabilities and discusses a few applications like digital signage and business continuity solutions.
- Published
- 2015
38. How Does IoT And Big Data Impact Network Capacity?
- Author
-
Brisbourne, Alex
- Subjects
INTERNET of things ,BIG data ,COMPUTER networking equipment ,MEDICAL care ,BANDWIDTHS - Abstract
the article talks about the impact of Internet of Things (IoT) and Big Data on capacity of machine to machine (M2M) networks. Topics discussed include cellular-connected M2M applications, application of Iot in healthcare, and Big Data in context with network bandwidth. Other topic discussed include implementation of sensors monitoring in modern automobile.
- Published
- 2014
39. M2M Hype Meets Reality.
- Author
-
Brisbourne, Alex
- Subjects
MACHINE-to-machine communications - Abstract
The article offers insight from Alex Brisbourne, president and chief operating officer of Kore Telematics, on the dismal growth of machine to machine (M2M) despite the prediction of stellar growth.
- Published
- 2012
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