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Results for “Growth”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

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At least 1,063 records · Page 59Linked to original sources
USGS2005

Effects of flooding regime and seedling treatment on early survival and growth of nuttall oak

Effects of flooding on survival and growth of three different types of Nuttall oak ( Quercus texana Buckl.) seedlings were observed at the end of third and fifth growing seasons at Yazoo National Wildlife Refuge, Mississippi, U.S.A. Three types of seedlings were planted in January 1995 in a split‐plot design, with four replications at each of two elevations on floodprone, former cropland in Sharkey clay soil. The lower of the two planting elevations was inundated for 21 days during the first growing season, whereas the higher elevation did not flood during the 5‐year period of this study. The three types of 1‐0 seedlings were bareroot seedlings, seedlings grown in containers (3.8 × 21–cm plastic seedling cones), and container‐grown seedlings inoculated with vegetative mycelia of Pisolithus tinctorius (Pers.) Coker. Survival of all the three seedling types was greatest at the lower, intermittently flooded elevation, indicating that drought and related effects on plant competition were more limiting to seedling survival than flooding. At the lower elevation, survival of mycorrhizal‐inoculated container seedlings was greater than that of noninoculated container seedlings. Survival among bareroot seedlings and inoculated container seedlings was not significantly different at either elevation. At the higher, nonflooded elevation, however, bareroot seedling survival was greater than the survival of container seedlings without inoculation. Differences were significant among the inoculated and the noninoculated container seedlings, with higher survival of inoculated seedlings at both elevations, though differences were only significant in year 3. At the end of the fifth year, height of bareroot seedlings was significantly greater than the heights of both types of container‐grown seedlings at both planting elevations. Because seedlings grown in the plastic seedlings cones did not survive better than the bareroot seedlings at either planting elevation, the bareroot stock appear to be the economically superior choice for regeneration in Sharkey soil.

Mississippi↗
USGS2017

Age and growth comparisons of Hovsgol grayling ( Thymallus nigrescens Dorogostaisky, 1923), Baikal grayling ( T. baicalensis Dybowski, 1874), and lenok ( Brachymystax lenok Pallas, 1773) in lentic and lotic habitats of Northern Mongolia

Despite concern over the conservation status of many Mongolian salmonids and the importance of their ecological role in Mongolia's aquatic ecosystems, little is known about their basic biology. Hovsgol grayling ( Thymallus nigrescens ) is endemic to Lake Hovsgol, Mongolia and listed as endangered on the Mongolian Red List. Baikal grayling ( T. baicalensis ) and lenok ( Brachymystax lenok ) are found in lakes and rivers throughout the Selenge drainage. A detailed study of the age and growth of these three salmonids was conducted based on 1,682 samples collected from July 2006 to July 2013 in Lake Hovsgol, its outlet the Eg River, and one of the Eg's largest tributaries, the Uur River. Our results suggest that Hovsgol grayling in particular can reach a much older maximum age (17 years in our samples) than previously believed based on aging from scales. Female Hovsgol grayling were heavier at a given length than their male counterparts. Lenok had a greater average length-at-age in Lake Hovsgol compared to the rivers and greater weight-at-length in the warmer Uur River than in the Eg; female lenok from the rivers had a greater average length-at-age than their male counterparts. This study provides critical new information for the management and conservation of these threatened salmonid species in Mongolia.

Journal of Applied Ichthyology↗
USGS2020

A model for the growth and development of wave-dominated deltas fed by small mountainous rivers: Insights from the Elwha River delta, Washington

Observations from ground-penetrating radar, sediment cores, elevation surveys and aerial imagery are used to understand the development of the Elwha River delta in north-western Washington, USA, which prograded as a result of two dam removals in late 2011. Swash-bar, foreshore and swale depositional elements are recognized within ground-penetrating radar profiles and sediment cores. A model for the growth and development of small mountainous river wave-dominated deltas is proposed based on observation of both the fluvial and deltaic settings. If enough sediment is available in the fluvial system, mouth-bars form after higher than average river discharge events, creating a large platform seaward of the subaqueous delta plain. Swash-bars form concurrently or within a month of mouth-bar deposition as a result of wave action. Fair-weather waves drive swash-bar migration landward and in the direction of littoral drift. The signature of swash-bar welding to the shoreline is landward-dipping reflections, as a result of overwash processes and slipface migration. However, most swash-bars are eroded by the river mouth, as only 10 of the 37 swash-bars that formed between August 2011 and July 2016 survived within the Elwha River delta. The swash-bars that do survive either amalgamate onto the shoreline or an earlier deposited swash-bar, forming a single larger barrier at the delta front. In asymmetrical deltas, the signature of swash-bar welding is more likely to be preserved on the downdrift side of the delta, where formation is more likely and accommodation behind newer swash-bars preserves older deposits. On small mountainous river deltas, welded swash-bars may be more indicative of a large sediment pulse to the system, rather than large hydrological events.

Washington↗
USGS2015

Remote sensing change detection methods to track deforestation and growth in threatened rainforests in Madre de Dios, Peru

Two forestry-change detection methods are described, compared, and contrasted for estimating deforestation and growth in threatened forests in southern Peru from 2000 to 2010. The methods used in this study rely on freely available data, including atmospherically corrected Landsat 5 Thematic Mapper and Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation continuous fields (VCF). The two methods include a conventional supervised signature extraction method and a unique self-calibrating method called MODIS VCF guided forest/nonforest (FNF) masking. The process chain for each of these methods includes a threshold classification of MODIS VCF, training data or signature extraction, signature evaluation, k-nearest neighbor classification, analyst-guided reclassification, and postclassification image differencing to generate forest change maps. Comparisons of all methods were based on an accuracy assessment using 500 validation pixels. Results of this accuracy assessment indicate that FNF masking had a 5% higher overall accuracy and was superior to conventional supervised classification when estimating forest change. Both methods succeeded in classifying persistently forested and nonforested areas, and both had limitations when classifying forest change.

Madre de Dios↗
USGS2018

Geomorphic expression of rapid Holocene silicic magma reservoir growth beneath Laguna del Maule, Chile

Large rhyolitic volcanoes pose a hazard, yet the processes and signals foretelling an eruption are obscure. Satellite geodesy has revealed surface inflation signaling unrest within magma reservoirs underlying a few rhyolitic volcanoes. Although seismic, electrical, and potential field methods may illuminate the current configuration and state of these reservoirs, they cannot fully address the processes by which they grow and evolve on geologic time scales. We combine measurement of a deformed paleoshore surface, isotopic dating of volcanism and surface exposure, and modeling to determine the rate of growth of a rhyolite-producing magma reservoir. The numerical approach builds on a magma intrusion model developed to explain the current, decade-long, surface inflation at >20 cm/year. Assuming that the observed 62-m uplift reflects several non-eruptive intrusions of magma, each similar to the unrest over the past decade, we find that ~13 km 3 of magma recharged the reservoir at a depth of ~7 km during the Holocene, accompanied by the eruption of ~9 km 3 of rhyolite. The long-term rate of magma input is consistent with reservoir freezing and pluton formation. Yet, the unique set of observations considered here implies that large reservoirs can be incubated and grow at shallow depth via episodic high-flux magma injections. These replenishment episodes likely drive rapid inflation, destabilize cooling systems, propel rhyolitic eruptions, and thus should be carefully monitored.

Laguna del Maule↗
USGS2005

Dating the growth of oceanic crust at a slow-spreading ridge

Nineteen uranium-lead zircon ages of lower crustal gabbros from Atlantis Bank, Southwest Indian Ridge, constrain the growth and construction of oceanic crust at this slow-spreading midocean ridge. Approximately 75% of the gabbros accreted within error of the predicted seafloor magnetic age, whereas ???25% are significantly older. These anomalously old samples suggest either spatially varying stochastic intrusion at the ridge axis or, more likely, crystallization of older gabbros at depths of ???5 to 18 kilometers below the base of crust in the cold, axial lithosphere, which were uplifted and intruded by shallow-level magmas during the creation of Atlantis Bank.

Science↗
USGS1986

A budget for continental growth and denudation

Oceanic crustal material on a global scale is re-created every 110 million years. From the data presented it is inferred that potential sialic material is formed at a rate of about 1.35 cubic kilometers per year, including hemipelagic volcanic sediments that accumulate at a rate of about 0.05 cubic kilometer per year. It is estimated that the influx of 1.65 cubic kilometers per year of terrigenous and biogenic sediment is deposited on the deep ocean, and this represents continental denudation. Because all this material is brought into a subduction zone, continental accretion rates, which could include all this material, may be as high as 3.0 cubic kilometers per year with a potential net growth for continents of 1.35 cubic kilometers per year.

Science↗
USGS1994

Isolation, growth, and metabolism of an obligately anaerobic, selenate- respiring bacterium, strain SES-3

A gram-negative, strictly anaerobic, motile vibrio was isolated from a selenate-respiring enrichment culture. The isolate, designated strain SES-3, grew by coupling the oxidation of lactate to acetate plus CO 2 with the concomitant reduction of selenate to selenite or of nitrate to ammonium. No growth was observed on sulfate or selenite, but cell suspensions readily reduced selenite to elemental selenium (Se 0 ). Hence, SES-3 can carry out a complete reduction of selenate to Se 0 . Washed cell suspensions of selenate-grown cells did not reduce nitrate, and nitrate-grown cells did not reduce selenate, indicating that these reductions are achieved by separate inducible enzyme systems. However, both nitrate-grown and selenate-grown cells have a constitutive ability to reduce selenite or nitrite. The oxidation of [ 14 C]lactate to 14 CO 2 coupled to the reduction of selenate or nitrate by cell suspensions was inhibited by CCCP (carbonyl cyanide m -chlorophenylhydrazone), cyanide, and azide. High concentrations of selenite (5 mM) were readily reduced to Se 0 by selenate-grown cells, but selenite appeared to block the synthesis of pyruvate dehydrogenase. Tracer experiments with [ 75 Se]selenite indicated that cell suspensions could achieve a rapid and quantitative reduction of selenite to Se 0 . This reduction was totally inhibited by sulfite, partially inhibited by selenate or nitrite, but unaffected by sulfate or nitrate. Cell suspensions could reduce thiosulfate, but not sulfite, to sulfide. These results suggest that reduction of selenite to Se 0 may proceed, in part, by some of the components of a dissimilatory system for sulfur oxyanions.

Nevada↗
USGS2002

Effect of growth conditions and staining procedure upon the subsurface transport and attachment behaviors of a groundwater protist

The transport and attachment behaviors of Spumella guttula (Kent), a nanoflagellate (protist) found in contaminated and uncontaminated aquifer sediments in Cape Cod, Mass., were assessed in flowthrough and static columns and in a field injection-and-recovery transport experiment involving an array of multilevel samplers. Transport of S. guttula harvested from low-nutrient (10 mg of dissolved organic carbon per liter), slightly acidic, granular (porous) growth media was compared to earlier observations involving nanoflagellates grown in a traditional high-nutrient liquid broth. In contrast to the highly retarded (retardation factor of ∼3) subsurface transport previously reported for S. guttula , the peak concentration of porous-medium-grown S. guttula traveled concomitantly with that of a conservative (bromide) tracer. About one-third of the porous-medium-grown nanoflagellates added to the aquifer were transported at least 2.8 m downgradient, compared to only ∼2% of the broth-grown nanoflagellates. Flowthrough column studies revealed that a vital (hydroethidine [HE]) staining procedure resulted in considerably less attachment (more transport) of S. guttula in aquifer sediments than did a staining-and-fixation procedure involving 4′,6′-diamidino-2-phenylindole (DAPI) and glutaraldehyde. The calculated collision efficiency (∼10 −2 for porous-medium-grown, DAPI-stained nanoflagellates) was comparable to that observed earlier for the indigenous community of unattached groundwater bacteria that serve as prey. The attachment of HE-labeled S. guttula onto aquifer sediment grains was independent of pH (over the range from pH 3 to 9) suggesting a primary attachment mechanism that may be fundamentally different from that of their prey bacteria, which exhibit sharp decreases in fractional attachment with increasing pH. The high degree of mobility of S. guttula in the aquifer sediments has important ecological implications for the protistan community within the temporally changing plume of organic contaminants in the Cape Cod aquifer.

Applied and Environmental Microbiology↗
USGS1974

Corynebacterial kidney disease of salmonids: Growth and serological studies on the causative bacterium

Comparative growth studies of 10 isolates of the Corynebacterium of salmonid kidney disease were quantified on four media. Greatest cell yield was obtained from Mueller-Hinton medium with 0.1% L-cysteine hydrochloride. Serological tests, in which rabbit antisera used against typical bacteria strains showed all to be antigenically homologous, provided a reliable method of identification.

Applied Microbiology↗
USGS1992

Volcano growth and evolution of the island of Hawaii

The seven volcanoes comprising the island of Hawaii and its submarine base are, in order of growth, Mahukona, Kohala, Mauna Kea, Hualalai, Mauna Loa, Kilauea, and Loihi. The first four have completed their shield-building stage, and the timing of this event can be determined from the depth of the slope break associated with the end of shield building, calibrated using the ages and depths of a series of dated submerged coral reefs off northwest Hawaii. On each volcano, the transition from eruption of tholeiitic to alkalic lava occurs near the end of shield building. The rate of southeastern progression of the end of shield building in the interval from Haleakala to Hualalai is about 13 cm/yr. Based on this rate and an average spacing of volcanoes on each loci line of 40-60km, the volcanoes required about 600 thousand years to grow from the ocean floor to the time of the end of shield building. They arrive at the ocean surface about midway through this period.

Hawaii↗
USGS1997

Ophiolitic basement to the Great Valley forearc basin, California, from seismic and gravity data: Implications for crustal growth at the North American continental margin

The nature of the Great Valley basement, whether oceanic or continental, has long been a source of controversy. A velocity model (derived from a 200-km-long east-west reflection-refraction profile collected south of the Mendocino triple junction, northern California, in 1993), further constrained by density and magnetic models, reveals an ophiolite underlying the Great Valley (Great Valley ophiolite), which in turn is underlain by a westward extension of lower-density continental crust (Sierran affinity material). We used an integrated modeling philosophy, first modeling the seismic-refraction data to obtain a final velocity model, and then modeling the long-wavelength features of the gravity data to obtain a final density model that is constrained in the upper crust by our velocity model. The crustal section of Great Valley ophiolite is 7-8 km thick, and the Great Valley ophiolite relict oceanic Moho is at 11-16 km depth. The Great Valley ophiolite does not extend west beneath the Coast Ranges, but only as far as the western margin of the Great Valley, where the 5-7-km-thick Great Valley ophiolite mantle section dips west into the present-day mantle. There are 16-18 km of lower-density Sierran affinity material beneath the Great Valley ophiolite mantle section, such that a second, deeper, "present-day" continental Moho is at about 34 km depth. At mid-crustal depths, the boundary between the eastern extent of the Great Valley ophiolite and the western extent of Sierran affinity material is a near-vertical velocity and density discontinuity about 80 km east of the western margin of the Great Valley. Our model has important implications for crustal growth at the North American continental margin. We suggest that a thick ophiolite sequence was obducted onto continental material, probably during the Jurassic Nevadan orogeny, so that the Great Valley basement is oceanic crust above oceanic mantle vertically stacked above continental crust and continental mantle.

California↗
USGS1997

Growth of a tectonic ridge during the Landers earthquake

The formation of tectonic ridges by localized vertical uplift along strike-slip faults has long been suspected, but the actual growth of a tectonic ridge during an earthquake has never been documented. During the 1992 Landers, California, earthquake sequence, an awl-shaped, dome-like topographic ridge along the Emerson fault zone increased its height at least 1 m concurrently with 3 m of right-lateral shift across the fault zone containing the ridge. Five deformation vectors within the ridge reveal dilatant behavior in addition to the uplift and shift on boundary faults.

Geology↗
USGS2011

Early growth of Kohala volcano and formation of long Hawaiian rift zones

Transitional-composition pillow basalts from the toe of the Hilo Ridge, collected from outcrop by submersible, have yielded the oldest ages known from the Island of Hawaii: 1138 ± 34 to 1159 ± 33 ka. Hilo Ridge has long been interpreted as a submarine rift zone of Mauna Kea, but the new ages validate proposals that it is the distal east rift zone of Kohala, the oldest subaerial volcano on the island. These ages constrain the inception of tholeiitic volcanism at Kohala, provide the first measured duration of tholeiitic shield building (≥870 k.y.) for any Hawaiian volcano, and show that this 125-km-long rift zone developed to near-total length during early growth of Kohala. Long eastern-trending rift zones of Hawaiian volcanoes may follow fractures in oceanic crust activated by arching of the Hawaiian Swell in front of the propagating hotspot.

Hawai'i↗
USGS2022

Quantifying large-scale continental shelf margin growth and dynamics across mid-Cretaceous Arctic Alaska with detrital zircon U-Pb dating

Sequence stratigraphy provides a unifying framework for integrating diverse observations to interpret sedimentary basin evolution; however, key time assumptions about stratigraphic elements spanning hundreds of kilometers are rarely quantified. We integrate new detrital zircon U-Pb (DZ) dates from 28 samples with seismic mapping to establish a chronostratigraphic framework across 800 km and ~20 m.y. for the middle-Cretaceous Torok-Nanushuk clinothem of Arctic Alaska (USA). Shelf-margin DZ dates indicate continent-scale sediment routing with Russian Chukotka provenance and provide reliable maximum depositional ages derived from arc volcanism. Shelf-margin advance rates display a clear relationship to toplap trajectories and provide empirical support for long-held inferences linking sediment supply to margin architecture. Two distinct shelf-margin growth regimes are evident: (1) a ca. 115–107 Ma phase of rapid ~50 km/m.y. shelf advance rates with mainly progradational trajectories; and (2) a ca. 107–98 Ma phase of moderate ~13 km/m.y. shelf advance rates with progradational-retrogradational-aggradational trajectories. We established a subsequent shelf–to–deep water correlation by independently dating ca. 98–95 Ma low shelf accommodation and basin-floor deposition as far as 240 km east that indicate lowstand shedding and a change to localized routing with Brooks Range provenance. Finally, we dated a ca. 95 Ma basin-wide transgression at deep-water to shelfal settings across 350 km that exhibits apparent synchroneity consistent with an event-significant surface. In one of the world’s largest foreland-basin clinothems, our work constrains the timing and duration of key depositional elements to test large-scale sequence stratigraphic assumptions, enables reliable correlation and quantification of sediment dynamics across 800 km, and captures the chronology of a giant regressive-transgressive cycle.

Alaska↗
USGS1988

Seasonal growth of the exotic submersed macrophyte Nitellopsis obtusa in the Detroit River of the Great Lakes

Seasonal growth and occurrence of an exotic submersed aquatic macrophyte, Nitellopsis obtusa , was monitored at the head of the Detroit River of the Great Lakes from June 1984 to April 1985. Nitellopsis obtusa first appeared in early July, increased in biomass from July to September, remained at relatively high biomass from September to late January, and decreased substantially as ice breakup began in mid-February. By March it had become senescent, lacking chlorophyll and disintegrating easily. Nitellopsis obtusa was therefore available as a source of food and shelter for benthic and juvenile fish populations in late fall and winter, when other macrophytes were absent.

Canadian Journal of Botany↗
USGS2013

Spatio-temporal variability in movement, age, and growth of mountain whitefish ( Prosopium williamsoni ) in a river network based upon PIT tagging and otolith chemistry

Connectivity of river networks and the movements among habitats can be critical for the life history of many fish species, and understanding of the patterns of movement is central to managing populations, communities, and the landscapes they use. We combined passive integrated transponder tagging over 4 years and strontium isotopes in otoliths to demonstrate that 25% of the mountain whitefish ( Prosopium williamsoni ) sampled moved between the Methow and Columbia rivers, Washington, USA. Seasonal migrations downstream from the Methow River to the Columbia River to overwinter occurred in autumn and upstream movements in the spring. We observed migration was common during the first year of life, with migrants being larger than nonmigrants. However, growth between migrants and nonmigrants was similar. Water temperature was positively related to the proportion of migrants and negatively related to the timing of migration, but neither was related to discharge. The broad spatio-temporal movements we observed suggest mountain whitefish, and likely other nonanadromous fish, require distant habitats and also suggests that management and conservation strategies to keep connectivity of large river networks are imperative.

Washington↗
USGS2018

Experimental whole-lake dissolved organic carbon increase alters fish diet and density but not growth or productivity

Negative relationships between dissolved organic carbon (DOC) concentration and fish productivity have been reported from correlative studies across lakes, but to date there have not been experimental tests of these relationships. We increased the DOC concentration in a lake by 3.4 mg L-1, using a before-after control-impact (BACI) design, to quantify the effects on the productivity and population structure of Largemouth Bass (Micropterus salmoides). Greater DOC reduced the volume of the epilimnion, the preferred habitat of Largemouth Bass, resulting in increased bass density. The likelihood that adult bass had empty diets decreased despite this increase in bass density; diet composition also changed. There was no apparent change in bass growth or condition. Overall, there was no net change in Largemouth Bass productivity. However, changes in YOY and juvenile recruitment and feeding success suggest the possibility that future effects could occur. Our results are the first to examine the effects of an increase in DOC on fish productivity through a five-year temporal lens, which demonstrates that the relationship between DOC and fish productivity is multi-dimensional and complex.

Canadian Journal of Fisheries and Aquatic Sciences↗