John A. Matthews
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View article: HAWC Performance Enhanced by Machine Learning in Gamma-hadron Separation
HAWC Performance Enhanced by Machine Learning in Gamma-hadron Separation Open
Improving gamma-hadron separation is one of the most effective ways to enhance the performance of ground-based gamma-ray observatories. With more than a decade of continuous operation, the High-Altitude Water Cherenkov (HAWC) Observatory h…
View article: Orbital Modulation of Gamma Rays up to 100 TeV from LS 5039
Orbital Modulation of Gamma Rays up to 100 TeV from LS 5039 Open
Gamma-ray binaries are luminous in gamma rays, composed of a compact object orbiting a massive companion star. The interaction between these two objects can drive relativistic outflows, either jets or winds, in which particles can be accel…
View article: Extended TeV Halos May Commonly Exist around Middle-Aged Pulsars
Extended TeV Halos May Commonly Exist around Middle-Aged Pulsars Open
Extended gamma-ray emission around isolated pulsars at TeV energies, also known as TeV halos, have been found around a handful of middle-aged pulsars. The halos are significantly more extended than their pulsar wind nebulae but much smalle…
View article: Schmidt-hammer exposure-age dating of talus slopes in upper Jostedalen, southern Norway: Interpreting the age and development of diachronous surfaces
Schmidt-hammer exposure-age dating of talus slopes in upper Jostedalen, southern Norway: Interpreting the age and development of diachronous surfaces Open
Schmidt-hammer exposure-age dating (SHD) was used to evaluate the surface age, dynamics and evolution of eight talus (scree) slopes located between ~520 and ~1010 m a.s.l. in the upper Jostedalen area of southern Norway. Statistically sign…
View article: Implications of an Early Holocene climax in solifluction and related periglacial activity on Juvflye, Jotunheimen (southern Norway), as revealed by Schmidt-hammer exposure-age dating
Implications of an Early Holocene climax in solifluction and related periglacial activity on Juvflye, Jotunheimen (southern Norway), as revealed by Schmidt-hammer exposure-age dating Open
View article: Schmidt-hammer R-values from glacially-scoured bedrock surfaces across glacier-foreland boundaries: Insights into Holocene weathering rates with implications for exposure-age dating
Schmidt-hammer R-values from glacially-scoured bedrock surfaces across glacier-foreland boundaries: Insights into Holocene weathering rates with implications for exposure-age dating Open
View article: Deglaciation of the highest mountains in Scandinavia at the Younger Dryas–Holocene transition: evidence from surface exposure‐age dating of ice‐marginal moraines
Deglaciation of the highest mountains in Scandinavia at the Younger Dryas–Holocene transition: evidence from surface exposure‐age dating of ice‐marginal moraines Open
Surface exposure–age dating was applied to rock surfaces associated with ice‐marginal moraines at elevations of ~1520–1780 m a.s.l. on the slopes of Galdhøpiggen and Glittertinden, the two highest mountains in Scandinavia located in the Jo…
View article: Repeated survey along the foreland of a receding Norwegian glacier reveals shifts in succession of beetles and spiders
Repeated survey along the foreland of a receding Norwegian glacier reveals shifts in succession of beetles and spiders Open
Glacier forelands provide important sites to study climate-forced ecological succession because a chronosequence is apparent along a single valley. However, most studies of invertebrate succession in forelands provide a single snapshot of …
View article: New evidence for active talus-foot rock glaciers at Øyberget, southern Norway, and their development during the Holocene
New evidence for active talus-foot rock glaciers at Øyberget, southern Norway, and their development during the Holocene Open
Synthetic aperture radar interferometry (InSAR) measurements demonstrate that lobate, blocky depositional landforms, located in southern Norway at an altitude of ~530 m above sea level, with an estimated mean annual air temperature of ~1.6…
View article: Early-Holocene moraine chronology, Sognefjell area, southern Norway: evidence for multiple glacial and climatic fluctuations within the Erdalen Event (~10.2‒9.7 ka)
Early-Holocene moraine chronology, Sognefjell area, southern Norway: evidence for multiple glacial and climatic fluctuations within the Erdalen Event (~10.2‒9.7 ka) Open
View article: Interpretation, age and significance of a relict paraglacial and periglacial boulder-dominated landform assemblage in Alnesdalen, Romsdalsalpane, southern Norway
Interpretation, age and significance of a relict paraglacial and periglacial boulder-dominated landform assemblage in Alnesdalen, Romsdalsalpane, southern Norway Open
View article: Evidence for rapid paraglacial formation of rock glaciers in southern Norway from <sup>10</sup>Be surface-exposure dating
Evidence for rapid paraglacial formation of rock glaciers in southern Norway from <sup>10</sup>Be surface-exposure dating Open
We evaluate the timing and environmental controls on past rock-glacier activity at Øyberget, upper Ottadalen, southern Norway, using in situ 10 Be surface-exposure dating on (1) boulders belonging to relict rock-glacier lobes at c. 530 m a…
View article: Schmidt-hammer exposure-age dating (SHD) of sorted stripes on Juvflye, Jotunheimen (central South Norway): Morphodynamic and palaeoclimatic implications
Schmidt-hammer exposure-age dating (SHD) of sorted stripes on Juvflye, Jotunheimen (central South Norway): Morphodynamic and palaeoclimatic implications Open
View article: Age and development of active cryoplanation terraces in the alpine permafrost zone at Svartkampan, Jotunheimen, southern Norway
Age and development of active cryoplanation terraces in the alpine permafrost zone at Svartkampan, Jotunheimen, southern Norway Open
Schmidt-hammer exposure-age dating (SHD) of boulders on cryoplanation terrace treads and associated bedrock cliff faces revealed Holocene ages ranging from 0 ± 825 to 8890 ± 1185 yr. The cliffs were significantly younger than the inner tre…
View article: Comparative numerical surface exposure-age dating (<sup>10</sup>Be and Schmidt hammer) of an early-Holocene rock avalanche at Alstadfjellet, Valldalen, southern Norway
Comparative numerical surface exposure-age dating (<sup>10</sup>Be and Schmidt hammer) of an early-Holocene rock avalanche at Alstadfjellet, Valldalen, southern Norway Open
Application of calibrated Schmidt-hammer surface-exposure dating (SHD) to the run-out debris of a rock avalanche at Alstadfjellet, Valldalen, southern Norway, has yielded ages that are consistent within uncertainties with terrestrial cosmo…
View article: Small rock‐slope failures conditioned by Holocene permafrost degradation: a new approach and conceptual model based on Schmidt‐hammer exposure‐age dating, Jotunheimen, southern Norway
Small rock‐slope failures conditioned by Holocene permafrost degradation: a new approach and conceptual model based on Schmidt‐hammer exposure‐age dating, Jotunheimen, southern Norway Open
Rock‐slope failures ( RSF s) constitute significant natural hazards, but the geophysical processes that control their timing are poorly understood. However, robust chronologies can provide valuable information on the environmental controls…
View article: Autosuccession in alpine vegetation: Testing the concept on an altitudinal bioclimatic gradient, Jotunheimen, southern Norway
Autosuccession in alpine vegetation: Testing the concept on an altitudinal bioclimatic gradient, Jotunheimen, southern Norway Open
View article: Snow-avalanche impact craters in southern Norway: Their morphology and dynamics compared with small terrestrial meteorite craters
Snow-avalanche impact craters in southern Norway: Their morphology and dynamics compared with small terrestrial meteorite craters Open
View article: Very low inheritance in cosmogenic surface exposure ages of glacial deposits: A field experiment from two Norwegian glacier forelands
Very low inheritance in cosmogenic surface exposure ages of glacial deposits: A field experiment from two Norwegian glacier forelands Open
Terrestrial cosmogenic nuclide dating has been widely used to estimate the surface exposure age of bedrock and boulder surfaces associated with deglaciation and Holocene glacier variations, but the effect of inherited age has been rarely d…
View article: Landform transitions from pronival ramparts to moraines and rock glaciers: a case study from the Smørbotn cirque, Romsdalsalpane, southern Norway
Landform transitions from pronival ramparts to moraines and rock glaciers: a case study from the Smørbotn cirque, Romsdalsalpane, southern Norway Open
Landform transitions are defined as intermediate forms that represent transient developmental stages between conventional landform types. This study evaluates possible cases of landform transitions from pronival (protalus) ramparts to mora…
View article: Relict Blockstreams at Insteheia, Valldalen-Tafjorden, Southern Norway: Their Nature and Schmidt Hammer Exposure Age
Relict Blockstreams at Insteheia, Valldalen-Tafjorden, Southern Norway: Their Nature and Schmidt Hammer Exposure Age Open
Two small blockstreams, the first such landforms to be recorded in the mountains of Scandinavia, are described from Insteheia, a col at 910 m asl on the watershed between Valldalen and Tafjorden (Møre og Romsdal), southern Norway. Both blo…
View article: Sediment fingerprinting and the mode of formation of singular and composite annual moraine ridges at two glacier margins, Jotunheimen, southern Norway
Sediment fingerprinting and the mode of formation of singular and composite annual moraine ridges at two glacier margins, Jotunheimen, southern Norway Open
Sedimentary variation within and between annual moraine ridges formed at Storbreen and Styggedalsbreen, Jotunheimen, during the 1980s and 1990s is investigated with a focus on processes and mechanisms of moraine-ridge formation. Tops and b…