number of downloads : ?
Title Transcription
ナカウミ コシンブ ニオケル コテイ ノ スイチュウ エイゾウ ソノ1 : フウソク ヘンカ ニ タイスル テイソウスイ ノ ドウタイ
Title Alternative
Lake fl oor images in the central part of Lake Nakaumi(part 1) : wind speed impacts on bottom water motion
File
language
jpn
Author
Nomura, Ritsuo
Horie, Yuzuru
Takata, Hiroyuki
Description
A long-term monitoring waterproof camera was installed on the bottom of Lake Nakaumi at a depth of 6.5 m, in order to observe bottom water movements and the ecology of brackish organisms. Over a six day period, Nov. 4–Nov. 9 2006, brackish water dynamics changed from stable to unstable conditions. Under the prior stable conditions, the sediment surface was covered with a bacterial mat. Strong winds, over 15 m/s, mixed upper and bottom water masses and the halocline disappeared for a short time in the middle of this period.
We show that winnowing of bottom sediments occurs at wind speeds greater than 10 m/s at this location; a small piece of bacterial mat was stripped off from the bottom sediment. When wind speed increased to greater than 12–13 m/s, bottom water turbulence was increased, with larger pieces of bacterial mat and sediment particles several centimeters in diamerter being resuspended. Water clarity decreased at this time. The bacterial mat was completely stripped off the sediment surface when wind speed exceeded 16 m/s. Suspended sediment caused water clarity to go to zero at this time.
Fish appeared in bottom waters soon after the wind-driven disruption of stratified water conditions, suggesting that oxygen-rich upper water were well mixed into oxygen-poor bottom water.
Subject
waterproof camera
long-term monitoring
bottom water
winnowing
wind speed
Journal Title
Laguna : 汽水域研究
Volume
14
Start Page
17
End Page
24
ISSN
21852995
Published Date
2007-12
NCID
AN10439529
Publisher
島根大学汽水域研究センター
NII Type
Departmental Bulletin Paper
Format
PDF
Text Version
出版社版
OAI-PMH Set
Estuary Research Center
このエントリーをはてなブックマークに追加