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from article Mustard
Black mustard (Brassica nigra). (Photo courtesy of Jennifer Anderson, USDA–NRCS PLANTS Database)
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from article Asian vegetables
A head of Chinese cabbage. (Credit: Jiang Hongyan/Shutterstock)
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from article Asian vegetables
Bok choy, also known as pak choy or Chinese mustard. (Credit: Agricultural Research Service, U.S. Department of Agriculture)
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from article Asian vegetables
Daikon (oriental winter radish) is a notable vegetable in Japan. (Credit: Franco Folini)
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from article Asian vegetables
Mung bean sprouts.
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from article Asian vegetables
Chinese okra. The length of the fruit can reach 30–38 cm (12–15 in.). (Credit: Forest and Kim Starr)
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from article Chert
Rhythmically bedded radiolarian chert from the Franciscan Complex. Diabio Range. California; of Late Jurassic age.
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from article Asbestos
The King City Asbestos Company mine in the Coalinga asbestos district of San Benito and Fresno Counties in west-central California. This large chrysotile mine was the last asbestos operation in the United States; the mine closed in 2002. (Credit:…
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from article Asbestos
Transmission electron photomicrographs of chrysotile asbestos (a) at 1000× magnification and (b) at 40,000× magnification, where the hollow-tube morphology is visible.
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from article Asbestos
Transmission electron photomicrographs of (a) amosite asbestos, (b) anthophyllite asbestos, (c) crocidolite asbestos, and (d) tremolite-actinolite asbestos. Note that tremolite and actinolite are part of a solid solution series and differ only in…
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from article Ebony
Persimmon (Diospyros virginiana). (Photograph by Dot Paul, National Resources Conservation Service, USDA)
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from article Tangerine
Tangerine fruits (Citrus reticulata). (Photo by Forest and Kim Starr)
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from article Pluton
Schematic block diagram showing the occurrence of the more common types of plutons.
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from article Forage crops
Bahia grass (Paspalum notatum), a popular warm-season grass used as a forage crop. (Photo by James H. Miller and Ted Bodner, Southern Weed Society)
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from article Forage crops
Alfalfa (Medicago sativa), the most important legume forage crop, cut and drying prior to its final harvest. (Photo by Howard F. Schwartz, Colorado State University)
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from article Nitrogen-fixing trees
Nitrogen-fixing Rhizobium bacteria form nodules on the roots of various legume trees. (Copyright © McGraw Hill)
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from article Nitrogen-fixing trees
A perennial nodule, several years old, formed on the roots of common or black alder (Alnus glutinosa) by symbiosis with Frankia (a nitrogen-fixing bacterium). (Copyright © McGraw Hill)
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from article Terrain areas
Distribution of terrain classes over the Earth. The subdivisions are intended to bring out only the most striking contrasts among land surfaces. Percentage of area occupied by each class is given in the text. (After G. T. Trewartha, A. H. Robinson…
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from article Kuroshio
General surface circulation of the North Pacific Ocean. (Adapted from Fig. 2.17 in J. R. Apfel, Principles of Ocean Physics, Academic Press, 1987)
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from article Kuroshio
Flow path of the Kuroshio and Kuroshio extension. Broken lines show the alternative "large-meander" path south of Japan. Smaller arrows show other flows described in the text. (After Y. G. Guo, The Kuroshio, Part II, Oceanog. Mar. Bio. Annu. Rev.,…
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from article Wheat
A sheaf of wheat (Triticum) surrounded by some small piles of seed (grain). (Credit: Scott Bauer/Agricultural Research Service, U.S. Department of Agriculture)
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from article Wheat
A combined harvester-thresher is used to harvest wheat. (Credit: Scott Bauer/Agricultural Research Service, U.S. Department of Agriculture)
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from article Wheat
Adaptation regions for wheat in the United States. (Credit: U.S. Department of Agriculture)
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from article Wheat
Wheat (Triticum) growing in a field. The wheat inflorescence is a spike bearing sessile spikelets arranged alternately on a zigzag rachis (main axis). (Credit: Tim McCabe/Natural Resources Conservation Service, U.S. Department of Agriculture)
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from article Wheat
Black stem rust of wheat, which produces urediniospores in reddish-brown pustules. The fungus Puccinia graminis f. sp. tritici is responsible for this plant disease. The inset shows a close-up view of an infected stem. (Credit: Agricultural Research…
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from article Wheat
Loose smut of wheat, caused by Ustilago tritici. (Credit: Erik Stromberg/Virginia Polytechnic Institute and State University)
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from article Marine biological sampling
Marine sampling devices. (a) Water sampling bottle with attached thermometer rack for recording water temperature at sampling depth. The brass messenger on the wire has just tripped the spring-loaded end closures (after S. Niskin, A…
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from article Marine biological sampling
Towed undulating vehicle system with some of its sensors. (Chelsea Instruments, Ltd., United Kingdom)
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from article Marine biological sampling
Data collected by a towed undulating vehicle along a transect in the ocean. (a) Temperature; °F = (°C × 1.8) + 32. (b) Salinity. (c) Chlorophyll a. (Chelsea Instruments, Ltd., United Kingdom)
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from article Marine biological sampling
United States Naval Electronics Laboratory box corer. (a) Side view with spade in open position. (b) Side view with spade in closed position. (c) Disengaged core box for processing sample. (After R. R. Hessler and P. A. Jumars, Abyssal community…
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from article Permian
Permian, the sixth period of the Paleozoic.
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from article Permian
Correlation of major Permian rock units.
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from article Permian
East-west section of the Permian System in its type area.
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from article Permian
Depositional and structural relationships in western Texas during Permian time.
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from article Permian
Section across the Capitan Reef Complex. 1 m = 3.3 ft; 1 km = 0.6 mi.
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from article Permian
Paleogeography during the earliest part of the Permian Period.
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from article Permian
Paleogeography near the middle of the Permian Period.
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from article Conic section
Four conic sections. (a) Circle. (b) Ellipse. (c) Parabola. (d) Hyperbola.
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from article Transform fault
Various types of transform fault mapped in parts of North and Central America. Area inside circle is shown in detail in Fig. 3.
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from article Transform fault
The effect of changing plate motion on transform faults and their fracture zones. (a) East-west plate motion; offset spreading axes with a left-lateral North Transform and a right-lateral South Transform. (b) Change in motion; a small rotation of…
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from article Transform fault
Map showing parts of the San Andreas and Gulf of California fault systems. Many minor but still earthquake-generating strike-slip fault zones have been omitted. The abandoned offshore fault zones, relics of a time when the plate boundary was closer…
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from article Ginger
Ginger (Zingiber officinale). (USDA)
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from article Cosmic spherules
Scanning electron photomicrographs of stony cosmic spherules about 300 μm in diameter collected from the mid-Pacific ocean floor. (a) Sphere with so-called turtleback texture, indicative of rapid cooling from a very hot molten droplet. (b) Sphere…
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from article Phenocryst
Granite (quartz monzonite) from the Sierra Nevada of California showing numerous phenocrysts of microcline feldspar in parallel orientation with banded structure of the rock. Hammer is 10 in. (25 cm) long. (USGS photograph by W. B.Hamilton)
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from article Reforestation
Forests and people in the world.
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from article Reforestation
Relative amounts of land needed to produce 1000 ft3 of wood per year. (1) Mature, upland, natural hardwood stand. (2) Pine plantation owned by a farmer and managed with minimum inputs. (3) Pine plantation managed by a forest company and managed with…
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from article Hill and mountain terrain
Cirque of the Towers in Shoshone National Forest, Wyoming, United States. (Photograph by Ron Olsen, USGS)
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from article Hill and mountain terrain
Several retreating small valley glaciers and deglacierized cirques and ridges east of the terminus of Tonsina Glacier, northcentral Chugach Mountains, Alaska, United States. Much of the ice disappeared during the last few decades of the twentieth…
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from article Hill and mountain terrain
View of eroded rock domes in the Black Hills National Forest, South Dakota, United States. (U.S. Forest Service)
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from article Guava
Fruit and leaves of the guava (Psidium guajava). (Photo courtesy of Forest and Kim Starr)
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from article Cloud physics
Conditions leading to birth of a cumulus cloud.
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from article Cloud physics
Diagram of the steps in the formation of rain.
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from article Cloud physics
Ice crystal types formed in various temperature ranges: (a) Thin hexagonal plate at 32 to 27°F (0 to −3°C), 18 to 10°F (−8 to −12°C), 3 to −13°F (−16 to −25°C). (b) Needles at 27 to 23°F (−3 to −5°C). (c) Hexagonal prismatic column at 23 to 18°F (−5…
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from article Tupelo
Leaves of black tupelo (Nyssa sylvatica). (Photograph courtesy of Larry Allain, USGS National Wetlands Research Center)
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from article Satellite meteorology
Plots of transmissivity variation with height (weighting factors) for seven wavelengths (or wavenumbers, given in cm−1) in the 15-m band for CO2. The shaded weight factor representing wavelength 13.966 μ (starred wavenumber 716 cm−1) shows the…
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from article Satellite meteorology
Schematic diagram of a circulation center or vorticity maximum and the formation of the comma-shaped cloud pattern. (a) Relative wind circulation (wind vectors along a north-south axis). (b) Lifting forms cloud (shaded region) ahead of the center,…
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from article Satellite meteorology
Water vapor image at the same time and location as in the color plate water vapor imagery can show features in clear areas such as the dark variations imaged over northern Kansas, central California, and another extending from northern Baja,…
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from article Satellite meteorology
Same water vapor image as shown in Fig. 4 but with contours depicting 500-hectopascal heights. The analysis has a resolution of about 60 km, whereas the image can show up to 8-km detail. The upper-level height contours align well with the water…
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from article Satellite meteorology
Use of satellite imagery for severe thunderstorm forecasting. The two visual images were taken 1 hour apart at 18 GMT (13 EST) and 19 GMT (14 EST) on May 6, 1975. The region includes Nebraska, Kansas, Iowa, and Missouri. (a) Surface weather…
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from article Pleistocene
Pleistocene, the first epoch of the Quaternary.
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from article Pleistocene
Pleistocene Ages/Stages and their temporal equivalents. (After B. U. Haq, Geological Time Table, 6th ed., Elsevier, Amsterdam, 2007)
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from article Pleistocene
Spread of the continental ice sheets over North America during various Pleistocene ice ages. (After R. F. Flint, Glacial and Quaternary Geology, Wiley, New York, 1971)
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from article Pleistocene
Two European mammals of the Pleistocene that ranged widely and died out before the close of the epoch. (a) Woolly rhino (Coelodonta antiquitatis) (after B. Kurten, Pleistocene Mammals of Europe, Weidenfeld and Nicolson, 1968). (b) Woolly mammoth…
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from article Kentucky coffee tree
Seeds of the Kentucky coffee tree (Gymnocladus dioica). (Photo courtesy of Steve Hurst, ARS Systematic Botany and Mycology Laboratory, USDA–NRCS PLANTS Database)
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from article Kentucky coffee tree
Kentucky coffee tree (Gymnocladus dioica). (a) Parts of branch showing leaf scars and winter buds. (b) Branch.
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from article Pistachio
Pistachios (Pistacia vera) from California. (Photo by Scott Bauer, Agricultural Research Service, U.S. Department of Agriculture)
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from article Seismic stratigraphy
Relation of strata to boundaries of depositional sequences. (a) At the upper boundary of a sequence, strata may terminate mainly as a result of erosion, toplap, or offlap (initially inclined strata may terminate mainly as a result of nondeposition)…
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from article Seismic stratigraphy
Diagram of a fan-shaped depositional unit. The unit was fed from an entrenched source (S) and deposited on the continental slope or basin floor. The pattern in the downdip direction is a progradational one of successive units being deposited seaward…
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from article Seismic stratigraphy
Portions of sonic logs (V) and seismic traces (seis.) for four thicknesses of sand units; the sands are shaded. (a) Variable lower Wade. (b) Variable Medrano. The appearance of the sands produces a significant change in seismic wave shape, but the…
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from article Seismic stratigraphy
Section through a 3D seismic volume in the Gulf of Mexico, showing a channel. The thin lines are arrival-time contours along a reflection event. They show the present-day relief on what was once the surface of the Earth. The different color…
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from article Seismic stratigraphy
Horizontal time slice at 900 ms through a 3D seismic volume in the Delaware Basin of New Mexico. The northern portion cuts through a relatively featureless carbonate platform. The edge of the platform has begun to break and slump as indicated by the…
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from article Seismic stratigraphy
Folded slice in the Delaware Basin, New Mexico. The northern part is a time slice at 1700 ms and the lower part is a vertical section at he southern edge of the time slice. (a) Seismic data. (b) Curvature attribute over the time-slice portion.…
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from article Silurian
Silurian, the third period of the of the Paleozoic Era.
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from article Catenary
Catenary and force triangle which keeps a portion of the string in equilibrium.
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from article Catenary
Relation of catenary to the tractrix which is its involute.
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from article Legendre functions
Legendre polynomials Pn(x), n = 2, 3, 4, 5.
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from article Legendre functions
Legendre functions of the second kind, Qn(x). (After E. Jahnke and F. Emde, Tables of Functions with Formulae and Curves, 4th ed., Dover Publications, 1945)
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from article Microbialite
Modern examples of microbialites. (a) Elongated stromatolites from hypersaline Hamelin Pool in Shark Bay, Western Australia. Scale bar: 0.5 m (1.64 ft). (b) Stromatolites found in the intertidal zone of Hamelin Pool. (c) Open-marine stromatolites…
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from article Double diffusion
Initial growth of salt fingers arises when parcels of warm, salty water intrude into the cold, freshwater below. Heat escapes from these parcels at a greater rate than salt, because of its much larger diffusivity. The resulting cold, salty water is…
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from article Authigenic minerals
Calcite concretion formed in Paleocene marine siltstone, Moeraki beach, New Zealand. Uncemented siltstone has been eroded away by wave action. Concretion is about 2 m (7 ft) in diameter, which is unusually large.
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from article Authigenic minerals
Scanning electron micrograph of authigenic kaolinite. The clay mineral formed from dissolution of calcic feldspar in a Miocene sandstone, San Joaquin basin, California.
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from article Authigenic minerals
Scanning electron micrograph of clinoptilolite zeolite (white crystals) on smectite-coated (dark background) sand grains. Sample is from Paleocene volcanic sandstone, Baja California, Mexico.
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from article Circle
A circle, with radius, diameter, and circumference indicated. (Credit: McGraw-Hill Education)
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from article Circle
Nine-point circle and Euler line PMH.
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from article Engineering geology
Diagram of a typical landslide monitoring instrumentation. (Credit: USGS)
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from article Engineering geology
Rock-physics laboratory instrumentation for testing triaxial shear strength. Shearing stresses tend to separate portions of the rock (or soil) mass. Faults and folds are examples of shear failures in nature. In engineering structures, every…
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from article Engineering geology
Geologic map that can be used to identify geologic hazards and for land-use planning. (Credit: USGS)
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from article Goat production
Domesticated goats (Capra hircus) raised for meat goat production. (Photo by Susan Boyer, Agricultural Research Service, U.S. Department of Agriculture)
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from article Goat production
Close-up view of a Saanen goat. (Photo by Milan Kořínek)
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from article Goat production
Mechanical (automatic) milking of a purebred Nigerian Dwarf dairy goat on an elevated stand. (Photo courtesy of Lesa Wilke, Bramblestone Farm, Ohio; www.bramblestonefarm.com)
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from article Sequence stratigraphy
Seismic reflection characterization. (a) Seismic transect across the western margin of Bimini Bank, Bahamas Platform, showing variations in seismic facies. Note the poorly reflective rocks at lower right, representing a sedimentary basement bounded…
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from article Sequence stratigraphy
Clastic-dominated sequence. (a) Model for clastic-dominated sequences on an extensional continental margin, showing the key stratigraphic surfaces and the four major systems tracts that develop within each sequence. Double-headed arrows show three…
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from article Cartography
Paper and smartphone maps for navigation. (Credit: Mmaxer/Shutterstock)
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from article Cartography
Distribution of chronic wasting disease of the deer family in North America, April 2018. (Credit: Bryan Richards, USGS National Wildlife Health Center)
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from article Cartography
Computer rendering of the topography of the 48 contiguous United States based on 12 million elevations. (USGS)
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from article Trihedron
Trihedron and trihedral angles.
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from article Trihedron
Spherical triangle ABC formed by intersection of sphere with a trihedron. The center of the sphere is at the vertex of the trihedron.
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from article Apple
Empire apple (Malus pumila). (Credit: Peggy Greb/Agricultural Research Service, United States Department of Agriculture)
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from article Apple
Apple trees in an orchard in late autumn. (Credit: Sandrine Bouvier/Alamy)
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from article Oolite
Plain light micrographs of thin sections of ooids and pisoids. (a) Oolite of Mississippian age, southwestern Indiana. (b) Pisoids from the hot springs of Karlovy Vary (Carlsbad), Czech Republic. The lower right pisoid shows a rock fragment nucleus…
