Note: Better configuration for "Graphic Plot"s intended for printing
& photocopying is as follows:
> Select options for plots
[x] Omit high/low times on plots (clears overlapping text) [Select for
4-week plots only.]
[x] Plot with lines only, not color-filled (graphical plot only)
> Pick colors for color elements (graphical plot only):
Falling/Ebb Color - black (x)
Rising/Flood Color - black (x)
==
Ocean Ups and Downs
I. Exploring tidal cycles (daily & monthly):
WWW Tide and Current Predictor
http://tbone.biol.sc.edu/tide/sitesel.html
Tidal Height and Current Site Selection
U.S. Upper East Coast (Maine through Virginia)
http://tbone.biol.sc.edu/tide/sites_useastupper.html
Edit/Find (on This Page)...
"Ocean City (fishing pier)" finds, "Ocean City (fishing pier), Maryland
[map]"
[Alternate procedure]
"Reagan" finds, "Reagan National Airport, Washington, D.C. [map]"
> Select display type
[x] Graphic Plot: size [640] by [240] pixels (more plot options below)
> Select presentation options
[2- or 3 days] Length of time to display (ignored by One-Month Calendars)
Note: Resulting graph displays the following times: 00; 02; 04; 06; 08;
10; 12; 14; 16; 18; 20; 22; 00.
> Starting time and time display options [use default settings]
> Select options for plots [use default settings]
Print graph only (move cursor over graphic; click on icon for "Print this
image"); label dates; then answer the following activity question(s) ...
Activity Questions, Part 1
Q. Describe as many patterns as you are able to recognize by looking at
the graph.
A. 3-4 tides per day, H-->L-->H, etc., ~6 hr. apart (~50 min.). Higher
high tides occur on the same side of Earth as the Moon. Tidal range varies
from day-to-day, according to the Moon phase.
Alternate Options:
Option 1 <-- DO NOT use this option!
--------
> Select presentation options
[1 week]
> Select options for plots
[x] Omit high/low times on plots (clears overlapping text)
Note: Resulting graph displays the following times: 00; 04; 08; 12; 16;
20; 00.
Option 2 <-- USE this option!
--------
> Select presentation options
[4 weeks] <-- one month
> Select options for plots
[x] Omit high/low times on plots (clears overlapping text)
Note: Resulting graph displays "00" times only, indicating midnight
(beginning of new day).
Print graph only (move cursor over graphic; click on icon for "Print this
image"); label dates; label dates of Moon phases (see reference, Part II
below), then answer the following activity question(s) ...
Activity Questions, Part 2
Q. What is the relationship between Moon phase and tidal range?
A. New/Full - greatest tidal range; Quarter phases - smallest tidal range.
Two-week cycle.
II. Correlating Moon phase with tidal range:
http://aa.usno.navy.mil/data/docs/MoonPhase.html
U.S. Naval Observatory Astronomical Applications Department
Phases of the Moon
Click on "2005".
For the current month (or several month period beg. w. current month),
record (in data table) the dates of New Moon, First Quarter, Full Moon, &
Last Quarter.
Q. Approximately how many days pass between phases, e.g., New Moon to
First Quarter, First Quarter to Full Moon, etc.? For a complete cycle of
Moon phases?
A. ~7 days (1 week); ~30 days (1 month).
==
Alternate Procedure:
Copy & paste sample graphs into MS Word document; embed related activity
questions. Photocopy & hand-out to students. E.g., MAY 22-24 (Full Moon on
23 May 2005) & 4-week time period (beginning with current date).
==
BSLG
Ocean Ups and Downs - Plotting and Predicting Tides
pp. 18-19
Data Analysis
1. Look at the tidal information for the day you were assigned. Complete
the information required below and do the calculations as indicated.
Times of high tides: first; next
Calculate the time between high tides: hrs mins
Times of low tides: first; next
Calculate the time between low tides: hrs mins
*Also calculate time difference between consecutive high- & low tides.
[better sequence of questions...]
3. Looking at one day of the class plot, describe at least two daily
patterns you see in the data.
2. Look at the pattern of tides during the month. Locate the high tide
that is highest and the high tide that is lowest. Write the dates for
those two events below. Do the same thing for the lowest low tide and the
highest low tide.
Date of highest high tide; Date of lowest high tide
Date of highest low tide; Date of lowest low tide
4. Looking at the entire month's data, you can see a pattern in the
tidal range. Describe the pattern.
5. Diagrams of the Moon phases will be placed over the appropriate dates
on the class tidal plots. You can see a relationship between the tides and
the phases of the Moon, especially around those dates found in your
answers to #2. Describe this relationship.
6. In this activity we have seen that the Moon, which is 384,000 km from
Earth, affects the ocean levels on Earth. What familiar force might
help explain how this happens and why?
7. The Sun also has an effect on the Earth's ocean tides. Why do you think
the effect of the Moon is much greater than the effect of the Sun?