Astronomy & Geology /Earth Science – Geology
Field Trip Overview
Rules of The Boat
Wear the proper clothing
Wear the proper shoes
Eat breakfast
Bring snacks
Do not run
Always keep one foot on the boat when looking over the edge
Let me know if you are feeling sick
What you should pay attention to
Collecting the water data on pages 41-44
Using this data to fill in the graph on pages 45-50
Secchi Disk readings page 53
Use this data to fill in the graph on page 54
Sediment survey data page 55
Cruise device Quiz 8 on Moodle
Salinity of Seawater
What is salinity
The amount of salt ions dissolved in the sea
It is measured electronically with a salinity meter
The salinity increases when the Electronic Conductivity increases
It is measured in ppt (parts per thousand) or written as ‰
The average salinity for sea water is between 33 ‰ and 37 ‰
Some factors that control the salinity
High evaporation rates
Inflow of river water
Dissolved Oxygen
Gasses dissolve in the oceans
Oxygen(O2) Carbon Dioxide (CO2)
Nitrogen Green house gasses
We are only going to look at the O2 and CO2 they are the most important to photosynthesis
Factors that control the levels of gasses
Water temperature , cold water will dissolve more gas
Partial pressure, the higher the pressure the more gas it holds
Biological factors, photosynthesis, respiration and decomposition
Photosynthesis
The process where plants require CO2 and sunlight to produce O2
It is confined to the photic zone, the upper most area of the surface of the ocean
The photic zone is measured using the Secchi Disk
The Secchi Disk measured extinction coefficient of the water, which is used to determine the decrease of light intensity.
Factors that change the photic zone
Clouds Sediment Plankton
Acidity of Seawater
pH or acidity of any substance is measured on a scale of 0-14
pH values less than 7 are acids
pH values equal to 7 are neutral
pH values higher than 7 are bases
The pH of sea water can range from 7.5 -8.4
With an average of 7.8
The pH is affected by the addition of CO2 gas
Temperature of Seawater
Determined by sunlight
It can only penetrate a max depth of about 300ft
Surface is warm
Deep oceans are very cold
Seasonal variation
Winter months are cooler
Summer months are warmer
Global variation
Poles are cooler
Equator is warmer
There no definite average temperatures of seawater
Cruise Devises
Florel-Ule Scale
Secchi Disk
Van Veen Mudgrab
Otter Trawl
Biological Dredge (Rock Dredge)
SCMI
SCMI
Location: 820 S. Seaside Ave. San Pedro, CA 901731
Date: October 21st
Time: arrive at 12:10 pm to leave by 12:30pm
Phone: (310) 519-3172
My Cell Phone: (626) 602-5422
