K. Furlong - Academia.edu (original) (raw)

Papers by K. Furlong

The Mw 7.1 Darfield (Canterbury) earthquake of 4 September 2010 (NZST) was the first earthquake i... more The Mw 7.1 Darfield (Canterbury) earthquake of 4 September 2010 (NZST) was the first earthquake in New Zealand to produce ground-surface fault rupture since the 1987 Edgecumbe earthquake. Surface rupture of the previously unrecognised Greendale Fault during the Darfield earthquake extends for at least 29.5 km and comprises an en echelon series of east-west striking, left-stepping traces. Displacement is predominantly dextral strike-slip, averaging ~2.5 m, with maxima of ~5 m along the central part of the rupture. Maximum vertical displacement is ~1.5 m, but generally < 0.75 m. The south side of the fault has been uplifted relative to the north for ~80% of the rupture length, except at the eastern end where the north side is up. The zone of surface rupture deformation ranges in width from ~30 to 300 m, and comprises discrete shears, localised bulges and, primarily, horizontal dextral flexure. At least a dozen buildings were affected by surface rupture, but none collapsed, largely ...

Journal of Volcanology and Geothermal Research, 1985

Mantle-derived magmas emplaced in the upper crust (depth <10 km) are in thermal disequilibrium wi... more Mantle-derived magmas emplaced in the upper crust (depth <10 km) are in thermal disequilibrium with the surrounding country rock. As a consequence of the large temperature contrasts not only will the magma cool quite rapidly, but the surrounding country rock will be heated and affected by large thermal stresses. Using coupled time dependent thermal-mechanical models, we find that: (a) a single-stage 3 km radius magma body has an eruptive life of on the order of 104 years; (b) near the magma-wall-rock boundary large thermal stresses develop over short time spans (10 years); and (c) material stoped into the chamber as a result of these thermal stresses will be assimilated either in the upper reaches of the chamber or at its base leaving a relatively uncontaminated central core. These results indicate that contamination of a primary magma by stoped crustal blocks is an efficient mechanism for producing hybrid lava sequences.

Bulletin of the Seismological Society of America, 2013

Geological Society of America Abstracts with Programs, 2017

Lithosphere, 2015

The Klamath Mountains province of northwestern California-southwestern Oregon is an anomalous ele... more The Klamath Mountains province of northwestern California-southwestern Oregon is an anomalous element in the Cascadia margin; these mountains have the highest average topography, the oldest rocks, and the only identified example of late Cenozoic detachment faulting in the coastal mountains of the Cascadia forearc. Low-temperature thermochronology (apatite fission-track, apatite [U-Th]/He) analyses from the central and southern Klamath Mountains province record two distinct exhumation events-a Cretaceous-Paleocene regional cooling and a southward-migrating locus of rapid cooling/exhumation in the middle Tertiary. This younger event is localized within the geographic extent of the La Grange fault. We infer that this pattern reflects two distinct processes of exhumation: regional surface erosion (older) and migrating localized tectonic exhumation (younger). At the southern limit of this region of rapid cooling, slickenside striations on the exposed La Grange fault surface record southward displacement of the upper plate along a shallowly dipping (~20°) detachment surface. Thermochronologic data constrain average dip of the fault to a few degrees, upper-plate thickness to <~6-8 km, and fault slip rate to <2 mm/ yr for a duration of 30 m.y. (ca. 45 Ma to 15 Ma). The fault dip is unusually low compared to that of typical detachment faults; the duration of this extensional event is unusually long compared to other detachment faults; the north-south (margin-parallel) slip direction is roughly perpendicular to that of other Klamath Mountains province faults; and the Eocene to early Miocene timing of extensional faulting does not correlate with recognized tectonic events in northern California. Mid-Tertiary tectonic events in the Oregon Coast Ranges provide a context for understanding the unusual mid-Tertiary tectonism in the Klamath Mountains province. Immediately north of the Klamath Mountains province, early Eocene accretion of a large early Cenozoic igneous province, the Siletz terrane, initiated a westward jump of active subduction. Accretion was followed by late Eocene margin-parallel extension in the Oregon Coast Ranges, recorded by formation of a regional dike swarm. Both the timing of tectonic exhumation and the direction of extension on the La Grange detachment fault suggest that mid-Tertiary tectonism in the southern Klamath Mountains province was likely driven by plate tectonics associated with the accretion of Siletzia and the reestablishment of subduction outboard of the accreted terrane.

Geophysical Research Letters, 2001

The Eastern California Shear Zone is bounded by the high heat flow region of the Basin and Range ... more The Eastern California Shear Zone is bounded by the high heat flow region of the Basin and Range province and the low heat flow region of the Sierra Nevada block. This difference in thermal state influences the rheology of the lower crust/upper mantle, resulting in a viscosity contrast between the two regions. We analyze the effect of such a contrast on the kinematics and dynamics of the shear zone with numerical models. This viscosity contrast drives asymmetric strain accumulation in the upper crust, producing an asymmetric surface velocity field. An additional consequence of this strain pattern is the potential for asymmetric co-seismic displacement during an earthquake.

Tectonics, 1988

Two end-member models of extension involving detachments have been developed. One model incorpora... more Two end-member models of extension involving detachments have been developed. One model incorporates a fault that soles at midcrustal level overlying a broad region of pure shear in the lower crest. The second, referred to as the simple shear model, includes a detachment continuing through the entire crest and terminating in a region of concentrated extension in the lower crest. Both models predict basins with no localized thermal effect. With the inclusion of flexural isostasy, both models predict footwall uplift whose amplitude and wavelength are controlled by the detachment geometry and the lithospheric strength. A gravity anomaly over the hanging wall block distinguishes the simple shear model from the intracmstal detachment model. The early Mesozoic basins of the eastern North America, believed to have formed as the result of the normal-slip reactivation of a Paleozoic thrust system as the Atlantic opened, are associated with distinctive hanging wall gravity highs. These gravity highs, the basin geometry, the lack of a thermal subsidence phase in the rift basins, and the presence of a highly extended and heated region to the east, suggest that the simple shear model may be

Abstract: This paper provides a photographic tour of the ground-surface rupture features of the G... more Abstract: This paper provides a photographic tour of the ground-surface rupture features of the Greendale Fault, formed during the 4 September 2010 Darfield earthquake. The fault, previously unknown, produced at least 29.5 km of strike-slip surface deformation of right-lateral (dextral) sense. Deformation, spread over a zone between 30 and 300 m wide, consisted mostly of horizontal flexure with subsidiary discrete shears, the latter only prominent where overall displacement across the zone exceeded about 1.5 m. A remarkable feature of this event was its location in an intensively farmed landscape, where a multitude of straight markers, such as fences, roads and ditches, allowed precise measurements of offsets, and permitted well-defined limits to be placed on the length and widths of the surface rupture deformation. The Mw 7.1 Darfield earthquake, centred about 40 km west of the city of Christchurch, New Zealand, struck at 4:35 a.m. on 4 September 2010, shattering the pre-dawn darkn...

4th Asia Pacific Meeting on Near Surface Geoscience & Engineering

The knowledge of the crustal strain rate tensor provides a description of geodynamic processes su... more The knowledge of the crustal strain rate tensor provides a description of geodynamic processes such as fault strain accumulation. We use interpolation of GPS geodetic measurements to derive the regional strain rate field for selected regions within the western North America plate boundary. We applied the interpolation scheme to data from the Eastern California Shear Zone, the Mendocino triple junction

In recent years, the global GEF(Green Energy Family) activities to preserve the global environmen... more In recent years, the global GEF(Green Energy Family) activities to preserve the global environment due to energy consumption have been implemented under the Kyoto Protocol for the Prohibition of Carbon Dioxide Emissions, RoHS (Restriction of Hazardous Substances directive), and WEEE(Waste Electrical and Electronice Equipment) are required to collect waste for the purpose of minimizing waste by integrating lighting and communication. In this paper, we constructed a controller that can control the illumination of RGB LED module by using fuzzy inference system and checking environmental factors(Illumination, distance to the subject, etc.) using microprocessor in real time.

The Mw 7.1 Darfield (Canterbury) earthquake of 4 September 2010 (NZST) was the first earthquake i... more The Mw 7.1 Darfield (Canterbury) earthquake of 4 September 2010 (NZST) was the first earthquake in New Zealand to produce ground-surface fault rupture since the 1987 Edgecumbe earthquake. Surface rupture of the previously unrecognised Greendale Fault during the Darfield earthquake extends for at least 29.5 km and comprises an en echelon series of east-west striking, left-stepping traces. Displacement is predominantly dextral strike-slip, averaging ~2.5 m, with maxima of ~5 m along the central part of the rupture. Maximum vertical displacement is ~1.5 m, but generally < 0.75 m. The south side of the fault has been uplifted relative to the north for ~80% of the rupture length, except at the eastern end where the north side is up. The zone of surface rupture deformation ranges in width from ~30 to 300 m, and comprises discrete shears, localised bulges and, primarily, horizontal dextral flexure. At least a dozen buildings were affected by surface rupture, but none collapsed, largely ...

Journal of Volcanology and Geothermal Research, 1985

Mantle-derived magmas emplaced in the upper crust (depth <10 km) are in thermal disequilibrium wi... more Mantle-derived magmas emplaced in the upper crust (depth <10 km) are in thermal disequilibrium with the surrounding country rock. As a consequence of the large temperature contrasts not only will the magma cool quite rapidly, but the surrounding country rock will be heated and affected by large thermal stresses. Using coupled time dependent thermal-mechanical models, we find that: (a) a single-stage 3 km radius magma body has an eruptive life of on the order of 104 years; (b) near the magma-wall-rock boundary large thermal stresses develop over short time spans (10 years); and (c) material stoped into the chamber as a result of these thermal stresses will be assimilated either in the upper reaches of the chamber or at its base leaving a relatively uncontaminated central core. These results indicate that contamination of a primary magma by stoped crustal blocks is an efficient mechanism for producing hybrid lava sequences.

Bulletin of the Seismological Society of America, 2013

Geological Society of America Abstracts with Programs, 2017

Lithosphere, 2015

The Klamath Mountains province of northwestern California-southwestern Oregon is an anomalous ele... more The Klamath Mountains province of northwestern California-southwestern Oregon is an anomalous element in the Cascadia margin; these mountains have the highest average topography, the oldest rocks, and the only identified example of late Cenozoic detachment faulting in the coastal mountains of the Cascadia forearc. Low-temperature thermochronology (apatite fission-track, apatite [U-Th]/He) analyses from the central and southern Klamath Mountains province record two distinct exhumation events-a Cretaceous-Paleocene regional cooling and a southward-migrating locus of rapid cooling/exhumation in the middle Tertiary. This younger event is localized within the geographic extent of the La Grange fault. We infer that this pattern reflects two distinct processes of exhumation: regional surface erosion (older) and migrating localized tectonic exhumation (younger). At the southern limit of this region of rapid cooling, slickenside striations on the exposed La Grange fault surface record southward displacement of the upper plate along a shallowly dipping (~20°) detachment surface. Thermochronologic data constrain average dip of the fault to a few degrees, upper-plate thickness to <~6-8 km, and fault slip rate to <2 mm/ yr for a duration of 30 m.y. (ca. 45 Ma to 15 Ma). The fault dip is unusually low compared to that of typical detachment faults; the duration of this extensional event is unusually long compared to other detachment faults; the north-south (margin-parallel) slip direction is roughly perpendicular to that of other Klamath Mountains province faults; and the Eocene to early Miocene timing of extensional faulting does not correlate with recognized tectonic events in northern California. Mid-Tertiary tectonic events in the Oregon Coast Ranges provide a context for understanding the unusual mid-Tertiary tectonism in the Klamath Mountains province. Immediately north of the Klamath Mountains province, early Eocene accretion of a large early Cenozoic igneous province, the Siletz terrane, initiated a westward jump of active subduction. Accretion was followed by late Eocene margin-parallel extension in the Oregon Coast Ranges, recorded by formation of a regional dike swarm. Both the timing of tectonic exhumation and the direction of extension on the La Grange detachment fault suggest that mid-Tertiary tectonism in the southern Klamath Mountains province was likely driven by plate tectonics associated with the accretion of Siletzia and the reestablishment of subduction outboard of the accreted terrane.

Geophysical Research Letters, 2001

The Eastern California Shear Zone is bounded by the high heat flow region of the Basin and Range ... more The Eastern California Shear Zone is bounded by the high heat flow region of the Basin and Range province and the low heat flow region of the Sierra Nevada block. This difference in thermal state influences the rheology of the lower crust/upper mantle, resulting in a viscosity contrast between the two regions. We analyze the effect of such a contrast on the kinematics and dynamics of the shear zone with numerical models. This viscosity contrast drives asymmetric strain accumulation in the upper crust, producing an asymmetric surface velocity field. An additional consequence of this strain pattern is the potential for asymmetric co-seismic displacement during an earthquake.

Tectonics, 1988

Two end-member models of extension involving detachments have been developed. One model incorpora... more Two end-member models of extension involving detachments have been developed. One model incorporates a fault that soles at midcrustal level overlying a broad region of pure shear in the lower crest. The second, referred to as the simple shear model, includes a detachment continuing through the entire crest and terminating in a region of concentrated extension in the lower crest. Both models predict basins with no localized thermal effect. With the inclusion of flexural isostasy, both models predict footwall uplift whose amplitude and wavelength are controlled by the detachment geometry and the lithospheric strength. A gravity anomaly over the hanging wall block distinguishes the simple shear model from the intracmstal detachment model. The early Mesozoic basins of the eastern North America, believed to have formed as the result of the normal-slip reactivation of a Paleozoic thrust system as the Atlantic opened, are associated with distinctive hanging wall gravity highs. These gravity highs, the basin geometry, the lack of a thermal subsidence phase in the rift basins, and the presence of a highly extended and heated region to the east, suggest that the simple shear model may be

Abstract: This paper provides a photographic tour of the ground-surface rupture features of the G... more Abstract: This paper provides a photographic tour of the ground-surface rupture features of the Greendale Fault, formed during the 4 September 2010 Darfield earthquake. The fault, previously unknown, produced at least 29.5 km of strike-slip surface deformation of right-lateral (dextral) sense. Deformation, spread over a zone between 30 and 300 m wide, consisted mostly of horizontal flexure with subsidiary discrete shears, the latter only prominent where overall displacement across the zone exceeded about 1.5 m. A remarkable feature of this event was its location in an intensively farmed landscape, where a multitude of straight markers, such as fences, roads and ditches, allowed precise measurements of offsets, and permitted well-defined limits to be placed on the length and widths of the surface rupture deformation. The Mw 7.1 Darfield earthquake, centred about 40 km west of the city of Christchurch, New Zealand, struck at 4:35 a.m. on 4 September 2010, shattering the pre-dawn darkn...

4th Asia Pacific Meeting on Near Surface Geoscience & Engineering

The knowledge of the crustal strain rate tensor provides a description of geodynamic processes su... more The knowledge of the crustal strain rate tensor provides a description of geodynamic processes such as fault strain accumulation. We use interpolation of GPS geodetic measurements to derive the regional strain rate field for selected regions within the western North America plate boundary. We applied the interpolation scheme to data from the Eastern California Shear Zone, the Mendocino triple junction

In recent years, the global GEF(Green Energy Family) activities to preserve the global environmen... more In recent years, the global GEF(Green Energy Family) activities to preserve the global environment due to energy consumption have been implemented under the Kyoto Protocol for the Prohibition of Carbon Dioxide Emissions, RoHS (Restriction of Hazardous Substances directive), and WEEE(Waste Electrical and Electronice Equipment) are required to collect waste for the purpose of minimizing waste by integrating lighting and communication. In this paper, we constructed a controller that can control the illumination of RGB LED module by using fuzzy inference system and checking environmental factors(Illumination, distance to the subject, etc.) using microprocessor in real time.