Blake Weissling - Academia.edu (original) (raw)

Papers by Blake Weissling

UVserva

En el año 2019 se llevaron a cabo estudios geofísicos en la montaña más alta de México, el volcán... more En el año 2019 se llevaron a cabo estudios geofísicos en la montaña más alta de México, el volcán Pico de Orizaba con una altura de 5636 m sobre el nivel del mar (snm). Mediante la aplicación de las técnicas geofísicas sísmica de refracción y georradar se determinaron espesores actuales del glaciar Jamapa y de sedimentos no-consolidados en la cuenca superior Jamapa. Los resultados son de gran importancia para recaudar información de esta área en particular, que ha sido zona de origen de varias formaciones de lahares (flujos de escombros) en el pasado reciente.

Data

Most of the world’s mountain glaciers have been retreating for more than a century in response to... more Most of the world’s mountain glaciers have been retreating for more than a century in response to climate change. Glacier retreat is evident on all continents, and the rate of retreat has accelerated during recent decades. Accurate, spatially explicit information on the position of glacier margins over time is useful for analyzing patterns of glacier retreat and measuring reductions in glacier surface area. This information is also essential for evaluating how mountain ecosystems are evolving due to climate warming and the attendant glacier retreat. Here, we present a non-comprehensive spatially explicit dataset showing multiple positions of glacier fronts since the Little Ice Age (LIA) maxima, including many data from the pre-satellite era. The dataset is based on multiple historical archival records including topographical maps; repeated photographs, paintings, and aerial or satellite images with a supplement of geochronology; and own field data. We provide ESRI shapefiles showing...

First International Meeting for Applied Geoscience & Energy Expanded Abstracts

Pico de Orizaba is the highest stratovolcano in Mexico and considered to be active. Apart from a ... more Pico de Orizaba is the highest stratovolcano in Mexico and considered to be active. Apart from a possible threat derived directly from a future eruption, large volcanic edifices like Pico de Orizaba, which are characterized by steep slopes, scarce vegetation cover on the upper cone (above 4000 m asl), and large quantities of unconsolidated material (volcanoclastic and glaciation-related) affected by different types of erosion and also hydrothermal activity, pose a considerable threat of secondary lahars and other mass movements. The existence of a glacier draining the Jamapa watershed needs a particular consideration in this context. Here, we present the first results of the SEG-GWB sponsored project: geophysical analysis employing Georadar and seismics on the Jamapa glacier and the proglacial ramp and analysis the parameters that influence these events' formation (trigger), including rainfall and seismic activity.

Annals of Glaciology

The widespread occurrence of snow-ice formation on the pack ice plays a critical role in the mass... more The widespread occurrence of snow-ice formation on the pack ice plays a critical role in the mass balance of Antarctic sea ice. The stable isotope composition, ice texture and salinity of eight ice cores, obtained from the Amundsen Sea during the Oden Southern Ocean 2010/11 expedition from late December 2010 to January 2011, were investigated to illustrate the snow-ice growth process and its contribution to sea-ice development. Most previous research has utilized δ18O as an index tracer to determine the percentages of core length that contain meteoric water, i.e. snow ice. However, this standard practice of snow-ice identification might be biased due to normally low-resolution isotopic measurements and mixing/diffusion processes between the snow ice and underlying ice layers. Snow-ice contributions in these ice cores based instead on an updated isotope mixing model are also presented. Depth profiles of ice texture and salinity are described to serve as representations of the structu...

The Cryosphere Discussions

Satellites have documented variability in sea ice areal extent for decades, but there are signifi... more Satellites have documented variability in sea ice areal extent for decades, but there are significant challenges in obtaining analogous measurements for sea ice thickness data in the Antarctic, primarily due to difficulties in estimating snow cover on sea ice. Sea ice thickness can be estimated from surface elevation measurements, such as those from airborne/satellite LiDAR, by assuming some snow depth distribution or empirically fitting with limited data from drilled transects from various field studies. Current estimates for large-scale Antarctic sea ice thickness have errors as high as ∼50%, and simple statistical models of small-scale mean thickness have similarly high errors. Averaging measurements over hundreds of meters can improve the model fits to existing data, though these results do not necessarily generalize to other floes. At present, we do not have algorithms that accurately estimate sea ice thickness at high resolutions. We use a convolutional neural network with laser altimetry profiles of sea ice surfaces at 0.2 m resolution to show that it is possible to estimate sea ice thickness at 20 m resolution with better accuracy and generalization than current methods (mean relative errors ∼15%). Moreover, the neural network does not require specifying snow depth/density, which increases its potential applications to other LiDAR datasets. The learned features appear to correspond to basic morphological features, and these features appear to be common to other floes with the same climatology. This suggests that there is a relationship between the surface morphology and the ice thickness. The model has a mean relative error of 20% when applied to a new floe from the region and season, which is much lower than the mean relative error for a linear fit (errors up to 47%). This method may be extended to lower-resolution, larger-footprint data such as such as IceBridge, and suggests a possible avenue to reduce errors in satellite estimates of Antarctic sea ice thickness from ICESat-2 over current methods, especially at smaller scale.

Oxygen and hydrogen stable isotopes (δ 18 O and δD) in precipitation collected in rain events fro... more Oxygen and hydrogen stable isotopes (δ 18 O and δD) in precipitation collected in rain events from 2015 to 2018 in San Antonio (SA), Central Texas, are presented in this research. The total correlation between δ 18 O and δD obtained here is similar to the Global Meteoric Water Line. However, variations of the regression line from 2015 to 2018 are likely caused by changes in moisture sources for the precipitation. Two severe convective storm events are investigated in this study. We collected and photographed 15 hailstones for the hailstorm of April 12th, 2016, northern SA. The isotopic analysis of the hailstone subsamples, together with their crystal structures, are examined here to provide information on the vertical profile of the moisture content, cloud droplet sizes, and temperature of the clouds in which the hailstones formed. Hourly precipitation samples of Hurricane Harvey were collected during a 45-hour span between August 25 and 27, 2017 in SA. The stable isotope composition of precipitation changed remarkably before, during, and after Hurricane Harvey, which was due to changes of moisture sources from terrestrial to oceanic sources of water vapor and sub-cloud dynamic processes.

The Guadalupe and San Antonio River basins of south-central Texas have a long history of catastro... more The Guadalupe and San Antonio River basins of south-central Texas have a long history of catastrophic flooding events. Recent events in July 2002 and October 1998 resulted in enormous property losses and dozens of deaths. More than 48,000 homes were damaged or destroyed during the 2002 event, when as much as 35 inches of rain fell in parts of the

Agu Fall Meeting Abstracts, Dec 1, 2007

Sea ice is a critical component of the Earth's climate system and is a highly complex media. ... more Sea ice is a critical component of the Earth's climate system and is a highly complex media. The physical characteristics are important in interpretation of remote sensing data. Sea ice characteristics such as snow surface topography, snow depth and ice thickness were derived from in situ measurements obtained during the J.C. Ross (ICEBell) and Oden Southern Ocean (OSO) expeditions during the austral summer of 2010-11. Select areas of sea ice floes in the Bellingshausen, Weddell and Amundsen Seas were measured using terrestrial scanning LiDAR (TSL) and also by conventional gridded and transect surveys. Snow depths were obtained at 2-5 meter sampling intervals and ice thickness was estimated by both electromagnetic induction (EMI) and auger drilling at 2-5 meter intervals. The LiDAR data is gridded to a 10cm rasterized data set. The field data from multiple floes in different regions provide a unique three dimensional perspective of sea ice elevation, snow depth and derived freeb...

The challenge of identifying and delineating subterranean habitat for endangered species in karst... more The challenge of identifying and delineating subterranean habitat for endangered species in karst environments has been addressed through the application of near-surface geophysical techniques. Electrical resistivity imaging (ERI) in both galvanic DC and capacitance-coupled modes has been applied to the problem of imaging subsurface voids, potentially conducive to karst invertebrate habitat, in two distinctly different geologic, geophysical, and environmental settings. Surveys were conducted in extrusive volcanic terrain on the south shore of Kauai, Hawaii, a site known for lava tube formation, and in limestone karst terrain in central Texas. The two study sites were distinctly different in their geophysical settings in terms of surface layer and subsurface background resistivities, values at the Kauai site ranging from 1000 - 5000 ohm-meters and at the Texas site 100 - 800 ohm-meters, values reflecting differing lithology, porosity, and pore fluid content. An Advanced Geosciences I...

Inner Space Caverns, discovered in the early 1960’s during construction of an Interstate Highway ... more Inner Space Caverns, discovered in the early 1960’s during construction of an Interstate Highway (IH 35) in central Texas, exists today as one of the largest caverns in the state from both a commercial perspective as well as surveyed extent. No known natural entrance exists today for the cave system, yet paleo-entrances did exist as evidenced by Pleistocene era mammal bones unearthed in various sections of the cave, particularly within or adjacent to in-cave debris/talus piles associated with paleo-collapse events of the cave ceiling. Until recently, cave surveyors have characterized the spatial extent of these collapse features from sub-surface surveys alone – no obvious surface evidence exists today for these sinks or collapses due to extensive land modifications, primarily associated with the overlying highway system. One such feature, known as Bone Sink 2, was delineated on cave maps as a single large collapse structure encompassing approximately 3500 m2, as evidenced from debri...

El Pico de Orizaba (5636 m) is located on the border between the States of Puebla and Veracruz, M... more El Pico de Orizaba (5636 m) is located on the border between the States of Puebla and Veracruz, Mexico and is the third highest mountain in North America, and the tallest peak of the Trans-Mexican Volcanic Belt. In topographic prominence it is ranked second in the world for volcanic peaks behind Mount Kilimanjaro and seventh in the world for all peaks. It is known internationally by mountaineers for moderate slopes, relatively stable weather, high elevation and exceptional climbing opportunities. Pico de Orizaba draws hundreds of visitors each year to climb the Gran Glaciar Norte (aka Jamapa Glacier) and supports numerous local guide and ancillary services. In terms of resource dependence, snow and glacier melt runoff from Pico de Orizaba provides an important water source for local communities surrounding the peak. Since an IGY (International Geophysical Year) study of the glacier in 1957-8 by J. Lorenzo, the Gran Glaciar Norte has seen a 65% loss of glacial area and a 500 m vertic...

Geotechnical issues associated with the longwall mining technique in American coal mines is an on... more Geotechnical issues associated with the longwall mining technique in American coal mines is an ongo¬ing area of concern for coal mine engineers and mine safety oversight groups. A proof-of-concept geophysi¬cal survey employing ground-penetrating radar (GPR) to image sedimentary rock strata immediately above and below a mined coal seam at an active longwall mine in Carbon Coun¬ty, Utah, was commissioned by the Spokane Research Labo¬ratory of the National Institute for Occupational Safety and Health (NIOSH).GPR is most commonly applied to the imag¬ing of geologic structure as a surface technique. Numerous examples can be found in the scientific and engineering lit¬erature of such applications for imaging near-surface coal seams and structural issues related to historic coal mine activity.The application of GPR to in situ, underground issues within active coal mines is both novel and experimental. In this particular application, the concept to be evaluated involved not so much that GPR...

Sinkholes and the Engineering and Environmental Impacts of Karst, 2008

Deep Sea Research Part II: Topical Studies in Oceanography, 2011

Although sea-ice extent in the Bellingshausen-Amundsen (BA) seas sector of the Antarctic has show... more Although sea-ice extent in the Bellingshausen-Amundsen (BA) seas sector of the Antarctic has shown significant decline over several decades, there is not enough data to draw any conclusion on sea-ice thickness and its change for the BA sector, or for the entire Southern Ocean. This paper presents our results of snow and ice thickness distributions from the SIMBA 2007 experiment

Deep Sea Research Part II: Topical Studies in Oceanography, 2011

Ice Station Belgica was commenced in late winter 2007 in the Bellingshausen Sea as part of Sea Ic... more Ice Station Belgica was commenced in late winter 2007 in the Bellingshausen Sea as part of Sea Ice Mass Balance in Antarctica (SIMBA), an IPY 2007 cruise on the research vessel N.B. Palmer. A primary objective was to build on the work of previous Antarctic drift station experiments to geophysically characterize sea ice in terms of thickness, surface and ice

Archaeological Prospection, 2012

The information content of the near-field coupling-wave zone of ground-penetrating radar is explo... more The information content of the near-field coupling-wave zone of ground-penetrating radar is explored in the context of cultural resource investigations at two archaeological sites in Washington State and New Mexico. While the coupling-wave zone is frequently assumed to be information-poor in the context of very shallow resources, and routinely filtered out for the benefit of accentuating deeper resources, this study advocates careful inspection of this data zone. In both case studies, cultural resources most likely related to animal/human/vehicular trails or trackways were detected in unprocessed (raw) horizontal amplitude slices. The ability of radar to 'see' these resources is conjectured to be related to soil or sediment compaction.

UVserva

En el año 2019 se llevaron a cabo estudios geofísicos en la montaña más alta de México, el volcán... more En el año 2019 se llevaron a cabo estudios geofísicos en la montaña más alta de México, el volcán Pico de Orizaba con una altura de 5636 m sobre el nivel del mar (snm). Mediante la aplicación de las técnicas geofísicas sísmica de refracción y georradar se determinaron espesores actuales del glaciar Jamapa y de sedimentos no-consolidados en la cuenca superior Jamapa. Los resultados son de gran importancia para recaudar información de esta área en particular, que ha sido zona de origen de varias formaciones de lahares (flujos de escombros) en el pasado reciente.

Data

Most of the world’s mountain glaciers have been retreating for more than a century in response to... more Most of the world’s mountain glaciers have been retreating for more than a century in response to climate change. Glacier retreat is evident on all continents, and the rate of retreat has accelerated during recent decades. Accurate, spatially explicit information on the position of glacier margins over time is useful for analyzing patterns of glacier retreat and measuring reductions in glacier surface area. This information is also essential for evaluating how mountain ecosystems are evolving due to climate warming and the attendant glacier retreat. Here, we present a non-comprehensive spatially explicit dataset showing multiple positions of glacier fronts since the Little Ice Age (LIA) maxima, including many data from the pre-satellite era. The dataset is based on multiple historical archival records including topographical maps; repeated photographs, paintings, and aerial or satellite images with a supplement of geochronology; and own field data. We provide ESRI shapefiles showing...

First International Meeting for Applied Geoscience & Energy Expanded Abstracts

Pico de Orizaba is the highest stratovolcano in Mexico and considered to be active. Apart from a ... more Pico de Orizaba is the highest stratovolcano in Mexico and considered to be active. Apart from a possible threat derived directly from a future eruption, large volcanic edifices like Pico de Orizaba, which are characterized by steep slopes, scarce vegetation cover on the upper cone (above 4000 m asl), and large quantities of unconsolidated material (volcanoclastic and glaciation-related) affected by different types of erosion and also hydrothermal activity, pose a considerable threat of secondary lahars and other mass movements. The existence of a glacier draining the Jamapa watershed needs a particular consideration in this context. Here, we present the first results of the SEG-GWB sponsored project: geophysical analysis employing Georadar and seismics on the Jamapa glacier and the proglacial ramp and analysis the parameters that influence these events' formation (trigger), including rainfall and seismic activity.

Annals of Glaciology

The widespread occurrence of snow-ice formation on the pack ice plays a critical role in the mass... more The widespread occurrence of snow-ice formation on the pack ice plays a critical role in the mass balance of Antarctic sea ice. The stable isotope composition, ice texture and salinity of eight ice cores, obtained from the Amundsen Sea during the Oden Southern Ocean 2010/11 expedition from late December 2010 to January 2011, were investigated to illustrate the snow-ice growth process and its contribution to sea-ice development. Most previous research has utilized δ18O as an index tracer to determine the percentages of core length that contain meteoric water, i.e. snow ice. However, this standard practice of snow-ice identification might be biased due to normally low-resolution isotopic measurements and mixing/diffusion processes between the snow ice and underlying ice layers. Snow-ice contributions in these ice cores based instead on an updated isotope mixing model are also presented. Depth profiles of ice texture and salinity are described to serve as representations of the structu...

The Cryosphere Discussions

Satellites have documented variability in sea ice areal extent for decades, but there are signifi... more Satellites have documented variability in sea ice areal extent for decades, but there are significant challenges in obtaining analogous measurements for sea ice thickness data in the Antarctic, primarily due to difficulties in estimating snow cover on sea ice. Sea ice thickness can be estimated from surface elevation measurements, such as those from airborne/satellite LiDAR, by assuming some snow depth distribution or empirically fitting with limited data from drilled transects from various field studies. Current estimates for large-scale Antarctic sea ice thickness have errors as high as ∼50%, and simple statistical models of small-scale mean thickness have similarly high errors. Averaging measurements over hundreds of meters can improve the model fits to existing data, though these results do not necessarily generalize to other floes. At present, we do not have algorithms that accurately estimate sea ice thickness at high resolutions. We use a convolutional neural network with laser altimetry profiles of sea ice surfaces at 0.2 m resolution to show that it is possible to estimate sea ice thickness at 20 m resolution with better accuracy and generalization than current methods (mean relative errors ∼15%). Moreover, the neural network does not require specifying snow depth/density, which increases its potential applications to other LiDAR datasets. The learned features appear to correspond to basic morphological features, and these features appear to be common to other floes with the same climatology. This suggests that there is a relationship between the surface morphology and the ice thickness. The model has a mean relative error of 20% when applied to a new floe from the region and season, which is much lower than the mean relative error for a linear fit (errors up to 47%). This method may be extended to lower-resolution, larger-footprint data such as such as IceBridge, and suggests a possible avenue to reduce errors in satellite estimates of Antarctic sea ice thickness from ICESat-2 over current methods, especially at smaller scale.

Oxygen and hydrogen stable isotopes (δ 18 O and δD) in precipitation collected in rain events fro... more Oxygen and hydrogen stable isotopes (δ 18 O and δD) in precipitation collected in rain events from 2015 to 2018 in San Antonio (SA), Central Texas, are presented in this research. The total correlation between δ 18 O and δD obtained here is similar to the Global Meteoric Water Line. However, variations of the regression line from 2015 to 2018 are likely caused by changes in moisture sources for the precipitation. Two severe convective storm events are investigated in this study. We collected and photographed 15 hailstones for the hailstorm of April 12th, 2016, northern SA. The isotopic analysis of the hailstone subsamples, together with their crystal structures, are examined here to provide information on the vertical profile of the moisture content, cloud droplet sizes, and temperature of the clouds in which the hailstones formed. Hourly precipitation samples of Hurricane Harvey were collected during a 45-hour span between August 25 and 27, 2017 in SA. The stable isotope composition of precipitation changed remarkably before, during, and after Hurricane Harvey, which was due to changes of moisture sources from terrestrial to oceanic sources of water vapor and sub-cloud dynamic processes.

The Guadalupe and San Antonio River basins of south-central Texas have a long history of catastro... more The Guadalupe and San Antonio River basins of south-central Texas have a long history of catastrophic flooding events. Recent events in July 2002 and October 1998 resulted in enormous property losses and dozens of deaths. More than 48,000 homes were damaged or destroyed during the 2002 event, when as much as 35 inches of rain fell in parts of the

Agu Fall Meeting Abstracts, Dec 1, 2007

Sea ice is a critical component of the Earth's climate system and is a highly complex media. ... more Sea ice is a critical component of the Earth's climate system and is a highly complex media. The physical characteristics are important in interpretation of remote sensing data. Sea ice characteristics such as snow surface topography, snow depth and ice thickness were derived from in situ measurements obtained during the J.C. Ross (ICEBell) and Oden Southern Ocean (OSO) expeditions during the austral summer of 2010-11. Select areas of sea ice floes in the Bellingshausen, Weddell and Amundsen Seas were measured using terrestrial scanning LiDAR (TSL) and also by conventional gridded and transect surveys. Snow depths were obtained at 2-5 meter sampling intervals and ice thickness was estimated by both electromagnetic induction (EMI) and auger drilling at 2-5 meter intervals. The LiDAR data is gridded to a 10cm rasterized data set. The field data from multiple floes in different regions provide a unique three dimensional perspective of sea ice elevation, snow depth and derived freeb...

The challenge of identifying and delineating subterranean habitat for endangered species in karst... more The challenge of identifying and delineating subterranean habitat for endangered species in karst environments has been addressed through the application of near-surface geophysical techniques. Electrical resistivity imaging (ERI) in both galvanic DC and capacitance-coupled modes has been applied to the problem of imaging subsurface voids, potentially conducive to karst invertebrate habitat, in two distinctly different geologic, geophysical, and environmental settings. Surveys were conducted in extrusive volcanic terrain on the south shore of Kauai, Hawaii, a site known for lava tube formation, and in limestone karst terrain in central Texas. The two study sites were distinctly different in their geophysical settings in terms of surface layer and subsurface background resistivities, values at the Kauai site ranging from 1000 - 5000 ohm-meters and at the Texas site 100 - 800 ohm-meters, values reflecting differing lithology, porosity, and pore fluid content. An Advanced Geosciences I...

Inner Space Caverns, discovered in the early 1960’s during construction of an Interstate Highway ... more Inner Space Caverns, discovered in the early 1960’s during construction of an Interstate Highway (IH 35) in central Texas, exists today as one of the largest caverns in the state from both a commercial perspective as well as surveyed extent. No known natural entrance exists today for the cave system, yet paleo-entrances did exist as evidenced by Pleistocene era mammal bones unearthed in various sections of the cave, particularly within or adjacent to in-cave debris/talus piles associated with paleo-collapse events of the cave ceiling. Until recently, cave surveyors have characterized the spatial extent of these collapse features from sub-surface surveys alone – no obvious surface evidence exists today for these sinks or collapses due to extensive land modifications, primarily associated with the overlying highway system. One such feature, known as Bone Sink 2, was delineated on cave maps as a single large collapse structure encompassing approximately 3500 m2, as evidenced from debri...

El Pico de Orizaba (5636 m) is located on the border between the States of Puebla and Veracruz, M... more El Pico de Orizaba (5636 m) is located on the border between the States of Puebla and Veracruz, Mexico and is the third highest mountain in North America, and the tallest peak of the Trans-Mexican Volcanic Belt. In topographic prominence it is ranked second in the world for volcanic peaks behind Mount Kilimanjaro and seventh in the world for all peaks. It is known internationally by mountaineers for moderate slopes, relatively stable weather, high elevation and exceptional climbing opportunities. Pico de Orizaba draws hundreds of visitors each year to climb the Gran Glaciar Norte (aka Jamapa Glacier) and supports numerous local guide and ancillary services. In terms of resource dependence, snow and glacier melt runoff from Pico de Orizaba provides an important water source for local communities surrounding the peak. Since an IGY (International Geophysical Year) study of the glacier in 1957-8 by J. Lorenzo, the Gran Glaciar Norte has seen a 65% loss of glacial area and a 500 m vertic...

Geotechnical issues associated with the longwall mining technique in American coal mines is an on... more Geotechnical issues associated with the longwall mining technique in American coal mines is an ongo¬ing area of concern for coal mine engineers and mine safety oversight groups. A proof-of-concept geophysi¬cal survey employing ground-penetrating radar (GPR) to image sedimentary rock strata immediately above and below a mined coal seam at an active longwall mine in Carbon Coun¬ty, Utah, was commissioned by the Spokane Research Labo¬ratory of the National Institute for Occupational Safety and Health (NIOSH).GPR is most commonly applied to the imag¬ing of geologic structure as a surface technique. Numerous examples can be found in the scientific and engineering lit¬erature of such applications for imaging near-surface coal seams and structural issues related to historic coal mine activity.The application of GPR to in situ, underground issues within active coal mines is both novel and experimental. In this particular application, the concept to be evaluated involved not so much that GPR...

Sinkholes and the Engineering and Environmental Impacts of Karst, 2008

Deep Sea Research Part II: Topical Studies in Oceanography, 2011

Although sea-ice extent in the Bellingshausen-Amundsen (BA) seas sector of the Antarctic has show... more Although sea-ice extent in the Bellingshausen-Amundsen (BA) seas sector of the Antarctic has shown significant decline over several decades, there is not enough data to draw any conclusion on sea-ice thickness and its change for the BA sector, or for the entire Southern Ocean. This paper presents our results of snow and ice thickness distributions from the SIMBA 2007 experiment

Deep Sea Research Part II: Topical Studies in Oceanography, 2011

Ice Station Belgica was commenced in late winter 2007 in the Bellingshausen Sea as part of Sea Ic... more Ice Station Belgica was commenced in late winter 2007 in the Bellingshausen Sea as part of Sea Ice Mass Balance in Antarctica (SIMBA), an IPY 2007 cruise on the research vessel N.B. Palmer. A primary objective was to build on the work of previous Antarctic drift station experiments to geophysically characterize sea ice in terms of thickness, surface and ice

Archaeological Prospection, 2012

The information content of the near-field coupling-wave zone of ground-penetrating radar is explo... more The information content of the near-field coupling-wave zone of ground-penetrating radar is explored in the context of cultural resource investigations at two archaeological sites in Washington State and New Mexico. While the coupling-wave zone is frequently assumed to be information-poor in the context of very shallow resources, and routinely filtered out for the benefit of accentuating deeper resources, this study advocates careful inspection of this data zone. In both case studies, cultural resources most likely related to animal/human/vehicular trails or trackways were detected in unprocessed (raw) horizontal amplitude slices. The ability of radar to 'see' these resources is conjectured to be related to soil or sediment compaction.