Robert H Webb
Datos Biográficos
| ID | 5600749 |
|---|---|
| NOMBRE | Robert H Webb |
| NOMBRES | Robert H |
| APELLIDO | Webb |
| FIRMA | WEBB R H |
| AFILIACIONES | Arizona Geological Survey |
| ORCID | 0000-0002-4525-3904 |
| VERIFICADO | Sí |
| TOTAL DE OBRAS | 11 |
| TOTAL DE CITAS | 8 |
| TOTAL COMO AUTOR | 11 |
| TOTAL COMO EDITOR | 4 |
| PRIMER AÑO DE PUBLICACIÓN | 1985 |
| AÑO MÁS RECIENTE DE PUBLICACIÓN | 2021 |
| ÍNDICE H | 1 |
The Spatial and Temporal Distribution of Radiocarbon Ages from Packrat Middens
Grand Canyon, A Century of Change
The Changing Mile Revisited
The book explores the respective parts played by man and climate in altering the face of the arid regions of southern Arizona and northwestern Mexico. The major portion of the volume is comprised of plates in which landscape photographs taken in the 19th and early 20th centuries are compared with modern photographs exposed, as nearly as possible, from the same aspects. A review is given of the salient features of the desert habitat; and the influ…
Design with the Desert
The modern southwestern cities of Phoenix, Tucson, Las Vegas, Albuquerque, and El Paso occupy lands that once supported rich desert ecosystems. Typical development activities often resulted in scraping these desert lands of an ancient living landscape, to be replaced with one that is human-made and dependent on a large consumption of energy and natural resources. Design with the Desert: Conservation and Sustainable Development explores the natura…
Design with the Desert
Ancient Floods, Modern Hazards
Repeat Photography
Repeat Photography
Peak discharge of a Pleistocene lava-dam outburst flood in Grand Canyon, Arizona, USA
The failure of a lava dam 165,000 yr ago produced the largest known flood on the Colorado River in Grand Canyon. The Hyaloclastite Dam was up to 366 m high, and geochemical evidence linked this structure to outburst-flood deposits that occurred for 32 km downstream. Using the Hyaloclastite outburst-flood deposits as paleostage indicators, we used dam-failure and unsteady flow modeling to estimate a peak discharge and flow hydrograph. Failure of t…
The Changing Mile Revisited
Lee's Ferry
Lee's Ferry
Accuracy of post-bomb 137Cs and 14C in dating fluvial deposits
The accuracy and precision of 137Cs and 14C for dating post-1950 alluvial deposits were evaluated for deposits from known floods on two rivers in Arizona. The presence of 137Cs reliably indicates that deposition occurred after intensive above-ground nuclear testing was initiated around 1950. There was a positive correlation between the measured level of 137Cs activity and the clay content of the sediments, although 137Cs was detected even in sand…
Spatial and Temporal Distribution of Radiocarbon Ages on Rodent Middens from the Southwestern United States
The analysis of rodent middens, principally deposited by packrats ( Neotoma sp), has rapidly become the most important paleoecologic and paleoclimatologic tool in the southwestern United States. The recent discovery of rodent middens created by stick-nest rats ( Leporillus sp) and rock wallabies ( Petrogale sp) in Australia (Green et al , 1983; P S Martin, oral commun, 1984) and by dassie rats ( Petromus typicus ) in South Africa (L Scott, oral c…
Late Holocene Vegetation Changes in Greenwater Valley, Mojave Desert, California
Small-scale late Holocene vegetation changes were determined from a series of 13 modern and fossil packrat middens collected from a site in the Greenwater Valley, northern Mojave Desert, California. Although the site is above the modern lower limit of Coleogyne ramosissima (black-brush), macrofossils of this shrub are only present in samples younger than 270 yr B.P. In order to measure changes more subtle than presence vs absence, macrofossil con…
The Changing Mile Revisited
The book explores the respective parts played by man and climate in altering the face of the arid regions of southern Arizona and northwestern Mexico. The major portion of the volume is comprised of plates in which landscape photographs taken in the 19th and early 20th centuries are compared with modern photographs exposed, as nearly as possible, from the same aspects. A review is given of the salient features of the desert habitat; and the influ…
Grand Canyon, A Century of Change
Spatial and Temporal Distribution of Radiocarbon Ages on Rodent Middens from the Southwestern United States
The analysis of rodent middens, principally deposited by packrats ( Neotoma sp), has rapidly become the most important paleoecologic and paleoclimatologic tool in the southwestern United States. The recent discovery of rodent middens created by stick-nest rats ( Leporillus sp) and rock wallabies ( Petrogale sp) in Australia (Green et al , 1983; P S Martin, oral commun, 1984) and by dassie rats ( Petromus typicus ) in South Africa (L Scott, oral c…
Late Holocene Vegetation Changes in Greenwater Valley, Mojave Desert, California
Small-scale late Holocene vegetation changes were determined from a series of 13 modern and fossil packrat middens collected from a site in the Greenwater Valley, northern Mojave Desert, California. Although the site is above the modern lower limit of Coleogyne ramosissima (black-brush), macrofossils of this shrub are only present in samples younger than 270 yr B.P. In order to measure changes more subtle than presence vs absence, macrofossil con…
Spatial and Temporal Distribution of Radiocarbon Ages on Rodent Middens from the Southwestern United States
The analysis of rodent middens, principally deposited by packrats ( Neotoma sp), has rapidly become the most important paleoecologic and paleoclimatologic tool in the southwestern United States. The recent discovery of rodent middens created by stick-nest rats ( Leporillus sp) and rock wallabies ( Petrogale sp) in Australia (Green et al , 1983; P S Martin, oral commun, 1984) and by dassie rats ( Petromus typicus ) in South Africa (L Scott, oral c…
Accuracy of post-bomb 137Cs and 14C in dating fluvial deposits
The accuracy and precision of 137Cs and 14C for dating post-1950 alluvial deposits were evaluated for deposits from known floods on two rivers in Arizona. The presence of 137Cs reliably indicates that deposition occurred after intensive above-ground nuclear testing was initiated around 1950. There was a positive correlation between the measured level of 137Cs activity and the clay content of the sediments, although 137Cs was detected even in sand…
Lee's Ferry
Lee's Ferry
The Changing Mile Revisited
Peak discharge of a Pleistocene lava-dam outburst flood in Grand Canyon, Arizona, USA
The failure of a lava dam 165,000 yr ago produced the largest known flood on the Colorado River in Grand Canyon. The Hyaloclastite Dam was up to 366 m high, and geochemical evidence linked this structure to outburst-flood deposits that occurred for 32 km downstream. Using the Hyaloclastite outburst-flood deposits as paleostage indicators, we used dam-failure and unsteady flow modeling to estimate a peak discharge and flow hydrograph. Failure of t…
Repeat Photography
Repeat Photography
Ancient Floods, Modern Hazards
Design with the Desert
The modern southwestern cities of Phoenix, Tucson, Las Vegas, Albuquerque, and El Paso occupy lands that once supported rich desert ecosystems. Typical development activities often resulted in scraping these desert lands of an ancient living landscape, to be replaced with one that is human-made and dependent on a large consumption of energy and natural resources. Design with the Desert: Conservation and Sustainable Development explores the natura…
Design with the Desert
The Spatial and Temporal Distribution of Radiocarbon Ages from Packrat Middens
Grand Canyon, A Century of Change
The Changing Mile Revisited
The book explores the respective parts played by man and climate in altering the face of the arid regions of southern Arizona and northwestern Mexico. The major portion of the volume is comprised of plates in which landscape photographs taken in the 19th and early 20th centuries are compared with modern photographs exposed, as nearly as possible, from the same aspects. A review is given of the salient features of the desert habitat; and the influ…
Geography (8 obras) · Archaeology (4 obras) · Desert (philosophy) (3 obras) · Geology (3 obras) · Geology and Paleoclimatology Research (3 obras) · Paleontology (3 obras) · Physical geography (3 obras) · Radiocarbon dating (3 obras) · American Environmental and Regional History (2 obras) · Archaeology and ancient environmental studies (2 obras)