




Study with the several resources on Docsity
Earn points by helping other students or get them with a premium plan
Prepare for your exams
Study with the several resources on Docsity
Earn points to download
Earn points by helping other students or get them with a premium plan
Community
Ask the community for help and clear up your study doubts
Discover the best universities in your country according to Docsity users
Free resources
Download our free guides on studying techniques, anxiety management strategies, and thesis advice from Docsity tutors
An activity for students to create a graph of monthly tides in San Diego, labeling the phases of the moon and identifying spring tides and neap tides. The document also discusses the impact of tides on various marine organisms, such as barnacles and burrowing species. Students will gain a better understanding of the causes of tides and how they affect the local ecosystem.
What you will learn
Typology: Exams
1 / 8
This page cannot be seen from the preview
Don't miss anything!
Objectives:
To create a graph of monthly tides in San Diego, and label the phases of the moon on the graph.
Time:
This activity requires one 55-minute class period if the graph is produced on a computer, or 2 to 3 class periods if the graph is produced by hand.
Background:
One of the most important abiotic factors affecting the Tijuana Estuary each day is the tide. This Ecology section of the guide to the Tijuana Estuary gives a very good description of the causes of tides, which can be very complicated. In general, tides are caused by the gravita- tional pull of the sun and moon on the earth, and by the centrifugal forces due to the earth's spin on its axis.
When the sun and the moon are on the same side of the earth, which happens during the new moon, their combined gravitational pull causes high tides to be higher and low tides to be lower, during any given period of time. These tides are known as spring tides (which have nothing to do with the spring season). A second, lower spring tide occurs each month when the sun and the moon are on opposite sides of the earth from each other, which occurs dur- ing the full moon. During the first quarter and third quarter phases of the moon, the gravita-
California Content Standard Investigation and Experimentation 1i
tional pull of the sun and the moon are in opposition to each other, causing lower high tides and higher low tides. These tides are called neap tides.
In general, most areas of the earth's coastlines experience two high tides and two low tides each day. These changing water levels have a dramatic effect on coastal and estuarine organisms. For instance, sedentary organisms that can't move around are exposed during low tides and submerged during high tides. These organisms must find means of adapting to these changing environmental conditions. San Diego has mixed tides, which means there are two low tides and two high tides each day, but they are uneven. One low tide is lower than the other and one high tide is higher than the other each day. This activity will give stu- dents a visual representation of the tides in San Diego during a one-month period. Students will be able to see the highest tides and lowest tides for the month, and will mark the spring tides, neap tides, and phases of the moon on their graph.
Materials:
Each student will need a copy of the Tide Chart (attached), and either a computer or graph paper. If computers are available for student use, they will need to have a software applica- tion such as Excel or any other application that can produce graphs. The activity can also be completed by hand on graph paper. These instructions are for graphs produced by hand. Each student will need three half-sheets of graph paper, cut vertically.
Procedure:
Answers to student questions: Note: You can have the students answer these questions on a separate piece of paper or on the back of their graphs.
You will be constructing a graph of San Diego tides for one month, determining and labeling the dates for the four phases of the moon, and labeling the spring tides and neap tides for the month.
Read the Tides section of the guide to the Tijuana Estuary in the Ecology chapter. This will give you a very good idea about the causes of tides. In general, there are two main forces that cause tides - the gravitational pull of the sun and the moon on the earth, and the centrifu- gal force due to the earth's rotation on its axis.
When the sun and the moon are on the same side of the earth, which happens during the new moon, their combined gravitational pull causes high tides to be higher and low tides to be lower. These tides are known as spring tides (which have nothing to do with the season spring). A second, lower spring tide occurs each month when the sun and the moon on oppo- site sides of the earth from each other, which occurs during the full moon. During the first quarter and third quarter phases of the moon, the gravitational pull of the sun and the moon are in opposition to each other, causing lower high tides and higher low tides. These tides are called neap tides.
In general, most areas of the earth's coastlines experience two high tides and two low tides each day. These changing water levels have a dramatic effect on coastal and estuarine organisms. For instance, sedentary organisms that can't move around are exposed during low tides and submerged during high tides. These organisms must find means of adapting to these changing conditions.
San Diego has mixed tides, which means there are two low tides and two high tides each day, but they are uneven. One low tide is lower than the other and one high tide is higher.