Woods Hole Oceanographic Institution

About: Woods Hole Oceanographic Institution is a nonprofit organization based out in Falmouth, Massachusetts, United States. It is known for research contribution in the topics: Population & Mantle (geology). The organization has 5685 authors who have published 18396 publications receiving 1202050 citations. The organization is also known as: WHOI.

Stress Triggering of the 1994 M = 6.7 Northridge, California, Earthquake by Its Predecessors

Abstract: A model of stress transfer implies that earthquakes in 1933 and 1952 increased the Coulomb stress toward failure at the site of the 1971 San Fernando earthquake. The 1971 earthquake in turn raised stress and produced aftershocks at the site of the 1987 Whittier Narrows and 1994 Northridge ruptures. The Northridge main shock raised stress in areas where its aftershocks and surface faulting occurred. Together, the earthquakes with moment magnitude M >/= 6 near Los Angeles since 1933 have stressed parts of the Oak Ridge, Sierra Madre, Santa Monica Mountains, Elysian Park, and Newport-lnglewood faults by more than 1 bar. Although too small to cause earthquakes, these stress changes can trigger events if the crust is already near failure or advance future earthquake occurrence if it is not.

The Current System in the Yellow and East China Seas

Abstract: During the 1990s, our knowledge and understanding of the current system in the Yellow and East China Seas have grown significantly due primarily to new technologies for measuring surface currents and making high-resolution three-dimensional numerical model calculations. One of the most important new findings in this decade is direct evidence of the northward current west of Kyushu provided by satellite-tracked surface drifters. In the East China Sea shelf region, these recent studies indicate that in winter the Tsushima Warm Current has a single source, the Kuroshio Branch Current in the west of Kyushu, which transports a mixture of Kuroshio Water and Changjiang River Diluted Water northward. In summer the surface Tsushima Warm Current has multiple sources, i.e., the Taiwan Warm Current, the Kuroshio Branch Current to the north of Taiwan, and the Kuroshio Branch Current west of Kyushu. The summer surface circulation pattern in the East China Sea shelf region changes year-to-year corresponding to interannual variations in Changjiang River discharge. Questions concerning the Yellow Sea Warm Current, the Chinese Coastal Current in the Yellow Sea, the current field southwest of Kyushu, and the deep circulation in the Okinawa Trough remain to be addressed in the next decade.

Consistent fractionation of 13C in nature and in the laboratory: growth-rate effects in some haptophyte algae.

Abstract: The carbon isotopic fractionation accompanying formation of biomass by alkenone-producing algae in natural marine environments varies systematically with the concentration of dissolved phosphate Specifically, if the fractionation is expressed by epsilon p approximately delta e - delta p, where delta e and delta p are the delta 13C values for dissolved CO2 and for algal biomass (determined by isotopic analysis of C37 alkadienones), respectively, and if Ce is the concentration of dissolved CO2, micromole kg-1, then b = 38 + 160*[PO4], where [PO4] is the concentration of dissolved phosphate, microM, and b = (25 - epsilon p)Ce The correlation found between b and [PO4] is due to effects linking nutrient levels to growth rates and cellular carbon budgets for alkenone-containing algae, most likely by trace-metal limitations on algal growth The relationship reported here is characteristic of 39 samples (r2 = 095) from the Santa Monica Basin (six different times during the annual cycle), the equatorial Pacific (boreal spring and fall cruises as well as during an iron-enrichment experiment), and the Peru upwelling zone Points representative of samples from the Sargasso Sea ([PO4] < or = 01 microM) fall above the b = f[PO4] line Analysis of correlations expected between mu (growth rate), epsilon p, and Ce shows that, for our entire data set, most variations in epsilon p result from variations in mu rather than Ce Accordingly, before concentrations of dissolved CO2 can be estimated from isotopic fractionations, some means of accounting for variations in growth rate must be found, perhaps by drawing on relationships between [PO4] and Cd/Ca ratios in shells of planktonic foraminifera

Shedding light on processes that control particle export and flux attenuation in the twilight zone of the open ocean

Abstract: Pelagic food webs drive a flux of .10 310 12 kg C yr 21 that exits surface waters, mostly via sinking particles through the ocean’s ‘‘biological pump.’’ Much of this particle flux is remineralized in the poorly studied waters of the twilight zone, i.e., the layer underlying the euphotic zone and extending to 1000 m. We present a reanalysis of selected upper-ocean studies of particulate organic carbon (POC) flux and relate these observations to a simple one-dimensional biological model to shed light on twilight zone processes. The ecosystem model first predicts particle flux from the base of the euphotic zone, and then its attenuation below based on transformations by heterotrophic bacteria and zooplankton, and active downward transport of surface-derived particles by zooplankton. Observations and simulations both suggest that future sampling strategies for the twilight zone should take regional variability of the euphotic zone depth (Ez) into account. In addition, conventional curvefitting of particle flux data (i.e., power law or exponential) skews our interpretation of twilight zone processes. To overcome these artifacts, we introduce two new terms: the Ez-ratio (POC flux at Ez relative to net primary production [NPP]) and T100 (the ratio of POC flux 100 m below Ez to POC flux at Ez). A comparison of NPP, Ezratios, and T100 provides a new set of metrics to classify the ocean into different regimes, representing high and low surface export and subsurface flux attenuation. The ocean’s ‘‘twilight zone’’ is defined as the layer below the sunlit euphotic zone extending to depths of about 1000 m. The use of this term dates back to at least Russell (1931) and colleagues, who were interested in controls on the vertical distribution of marine macroplankton. The concept of sinking particles raining through this layer to the deep sea is also not new, as Agassiz (1888) and others explored deep-sea organisms and their nourishment from above. However, the advent of modern sediment trapping to intercept and capture the flux of settling ocean particles began much later, in the 1960s–1970s (Berger 1971; Honjo 1976; Soutar et al. 1977). Sediment traps allowed assessment of the relationship among surface algal productivity, particle export, and attenuation through the twilight zone (Berger et al. 1989). In addition to sinking particles, mixing