Real and apparent changes in sediment deposition rates through time

Real and Apparent Changes in Sediment Deposition Rates Through Time

Field measurements show that estimated sediment deposition rate decreases as a power law function of the measurement interval. This apparent decrease in sediment deposition has been attributed to completeness of the sedimentary record; the effect arises because of incorporation of longer hiatuses in deposition as averaging time is increased. We demonstrate that a heavy-tailed distribution of pe...

Semantic Changes in Apparent Time

0. Introduction Semantic changes have been scientifically studied for more than 150 years (Ner-lich 1992). All along this history, successive generations of scholars have adopted at least three different theoretical frameworks (Magué 2005). Chronologically, the first trend focused on the identification of the different kinds of semantic changes a lexeme can undergo. This taxonomist trend culmin...

Recent changes in sediment accumulation rates in Adventfjorden, Svalbard*

Recent sediment accumulation rates in Adventfjorden (Svalbard), a small subpolar fjord, were determined by Pb and Cs dating. Modern rates in the central basin decrease downfjord from 1.87 to 0.87 cm y−1 (2.6 to 1.19 g cm−2 y−1). Comparison of the modern values (1986–2001) with older ones (1963–86) reveals a marked increase in sediment accumulation rates in the last ten years. This correlates we...

Comparison of Sediment Load Models in Predicting Sediment Deposition Patterns

Real-time measurement of particulate matter deposition in the lung.

Air pollution and cigarette smoke are recognized health risks. A method was developed for the measurement of the deposition fraction (DF) of polydisperse particulate matter (PM) in human airways. Ten normal volunteers [three females, age range 18-67 years, mean age (SD) 43.9 (14)] made single breath exhalations after inhalation to total lung capacity. The exhaled breath was diverted to a multic...