The fluorescent tracer experiment on Holiday Beach near Mugu Canyon, Southern California

Abstract

For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment-visit http://www.usgs.gov or call 1-888-ASK-USGS For an overview of USGS information products, including maps, imagery, and publications, visit http://www.usgs.gov/pubprodTo order this and other USGS information products, visit http://store.usgs.gov Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.Although this report is in the public domain, permission must be secured from the individual copyright owners to reproduce any copyrighted material contained within this report. AbstractAfter revisiting sand tracer techniques originally developed in the 1960s, a range of fluorescent coating formulations were tested in the laboratory. Explicit steps are presented for the preparation of the formulation evaluated to have superior attributes, a thermoplastic pigment/dye in a colloidal mixture with a vinyl chloride/vinyl acetate copolymer. In September 2010, 0.59 cubic meters of fluorescent tracer material was injected into the littoral zone about 4 kilometers upcoast of Mugu submarine canyon in California. The movement of tracer was monitored in three dimensions over the course of 4 days using manual and automated techniques. Detailed observations of the tracer's behavior in the coastal zone indicate that this tracer successfully mimicked the native beach sand and similar methods could be used to validate models of tracer movement in this type of environment. Recommendations including how to time successful tracer studies and how to scale the field of view of automated camera systems are presented along with the advantages and disadvantages of the described tracer methodology.

Observation of Sediment Dynamics in the Nearshore Region using Fluorescent Sand Tracers

“…1. はじめに 砂浜海岸の沿岸域の地形形状は、砕波、波、流 れ等による底質の浮遊や岸沖方向・沿岸方向への 漂砂により時々刻々変化している．特に、砕波帯 では活発な底質移動が生じることから、砕波によ る底質浮遊(例えば、 [1,2]) 、波・流れによる影 響(例えば、 [3,4])などの検討が数多くなされて いる。また、主に砕波帯沖側に形成されるアウタ ーバー(沿岸砂州)に関しても、その形成(例え ば、 [5])や移動(例えば、 [6,7])に関する検討 がなされている。また、遡上帯に関しても底質移 動量が海岸侵食、堆積に直結することから、漂砂 量の算出(例えば、 [8]) 、高波浪時と静穏時の汀 線移動動態把握(例えば、 [9,10]) 、また、堆積性 地形であるバームの侵食堆積 [11]やその漂砂量分 布特性の検討 [12] [13]) 、構造物周りの底質移 動動態 [14]、沿岸漂砂 [15]、また底質の鉛直混合 の検討(例えば、 [16,17])などがなされている． 国内においても、底質移動方向と移動速度、鉛直 混合過程 [18]、沿岸域での底質移動調査 [19] Fig. 2 Observed time series data, (a) 2014 observations and (b) 2015 observations; (i) significant wave height, (ii) significant wave period, (iii) wave direction and (iv) wind speed.…”