Name: ___________________________________________ Date: __________________ Period: ______
Measuring Sea Level Change
What is sea level?
__________________________________________________________________________________
Sea Level Variations:
 Sea levels change _______________________, due to ____________________. Sea level rises and
falls every _________hours at most places or every _______ hours at some locations. This is called
__________________________________________. Sea level also varies
______________________________. e.g., in Tampa Bay the water level tends to be _______________
in the summer and __________________in the winter.
Sea Level Variations: Multi-year changes
 Sea level also varies in terms of ________________. e.g., during ______________ years, the sea level
along the US ___________________ coast tends to be higher than during ____________________
years.
Sea Level Variations: Irregular changes
 During a storm the sea level can ___________ very fast to a level that is much ______________ than
normal level, this is called storm ______________. During a ___________________ the sea level can
rise and fall EXTREMELY fast in a few __________________.
Let’s take a look at the History and Technology of measuring sea level
 Back in the old days, we measure sea level with a stilling well, (just like we measured the water table
on land, in a well….). Today, we measure sea level with much more sophisticated equipment than the
stilling well, but the principal remains similar.
Let’s take a closer look at a modern water level measurement station
 Housing: _________________________________________________________________________
 Solar panel: _________________________________________________________________________
 Sensor: ___________________________________________________________________________
 Satellite: _______________________________________________________________________
 Computer: _________________________________________________________________________
 Stilling well: ________________________________________________________________________
 Acoustic sensor: ______________________________________________________________________
The previous notes illustrate how we measure water level at the coast, then how do we measure water level
in the vast ocean?
 It turns out that we could not measure water level in the _________ ___________until about ____
years ago, when we began to have ________________ that can accurately measure
_____________________. This is called satellite ___________________________.
What causes sea level change?
 ______________: The attractions from the Sun and the Moon





Thermal expansion: Water ___________________ when becomes warmer
_______________________________ ice melting: Will add water to the ocean
Strong wind associated with storms: Will “pile” water up along the shoreline, call storm
_____________
Plate tectonics: Will change the ________________ of the ocean ______________________
Global warming:
o ________________________________________ and
_________________________________________