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Re: Dynamic Planet B/C
Posted: December 31st, 2014, 5:02 pm
by Watergirl
JT016 wrote:John Richardsim wrote:JT016 wrote:How would I go about solving a question like this:
"You are studying the sediment layers in an abyssal plain. If the sound is picked up by the receiver 5.92 seconds after leaving the source, how deep is the water? Assume the sound is travelling close to its maximum rate in water."
Would I use 1560 m/s as the speed of sound (found
HERE)? If so , would I get 9235.2m deep?
Uh, don't forget that the sound has to travel back to the receiver after reaching the bottom, so you need to cut the time in half.
Good thing I asked. I forgot to do that. Thanks

So 4617.6m
Just asking. How did you determine that you had to use 1560m/s as the speed of sound for this equation? I thought the speed of sound was supposed to be 1500 m/s.
Re: Dynamic Planet B/C
Posted: January 1st, 2015, 9:16 am
by John Richardsim
Watergirl wrote:JT016 wrote:How would I go about solving a question like this:
"You are studying the sediment layers in an abyssal plain. If the sound is picked up by the receiver 5.92 seconds after leaving the source, how deep is the water? Assume the sound is travelling close to its maximum rate in water."
Would I use 1560 m/s as the speed of sound (found
HERE)? If so , would I get 9235.2m deep?
Just asking. How did you determine that you had to use 1560m/s as the speed of sound for this equation? I thought the speed of sound was supposed to be 1500 m/s.
They got 1560 m/s in the
speed of sound in seawater section of that Wikipedia article (according to the section above it, the speed of sound in freshwater is almost 1500 m/s). However, the speed of sound in seawater will vary depending mainly on temperature, salinity, and pressure, each of which varies with depth. The figure of 1560 m/s in the text does not address any of those factors, so I would be skeptical about putting it in my notes at all. I personally think most tests would give the specific speed it wants you to use, which would probably be something along the lines of "Assuming an average speed of sound of _____..."
Re: Dynamic Planet B/C
Posted: January 1st, 2015, 10:00 am
by SOnerd
azuritemalachite wrote:SOnerd wrote:Does anyone know what we have to know about topographic maps?
I've studied stuff like contour lines and stuff. Is there anything else?
Last year with glaciers you had to identify features on a topographic map so the testmakers should have atleast something about sediments and sea-floor features.
I found some stuff involving bathymetric maps, which could be on a test..
https://www.google.com/search?q=bathyme ... ow+to+read
(Click on the second hit, I'm not sure how to upload word docs on here)
http://en.wikipedia.org/wiki/Bathymetric_chart
http://www.ehow.com/how_5087879_read-de ... tours.html
EDIT- Do you guys know what sorts of questions will be asked about maps?
Re: Dynamic Planet B/C
Posted: January 2nd, 2015, 1:12 pm
by sscharter
Hey,
So this is my first time doing this event and I was wondering what is the best way to go about studying...
I have a textbook and I am taking notes on all the information, but would that be enough? Is this the first year the event is using those NGSS practices?
Re: Dynamic Planet B/C
Posted: January 2nd, 2015, 3:11 pm
by John Richardsim
sscharter wrote:Hey,
So this is my first time doing this event and I was wondering what is the best way to go about studying...
I have a textbook and I am taking notes on all the information, but would that be enough? Is this the first year the event is using those NGSS practices?
Yeah, textbooks are a good way to go (most of the studying I've done so far has been from a textbook). In addition to textbooks, look around the web for stuff. A couple of other good starting places are the
NOAA Resources and
NOAA Oceans and Coasts.
Re: Dynamic Planet B/C
Posted: January 2nd, 2015, 3:17 pm
by JT016
John Richardsim wrote:Watergirl wrote:JT016 wrote:
Just asking. How did you determine that you had to use 1560m/s as the speed of sound for this equation? I thought the speed of sound was supposed to be 1500 m/s.
They got 1560 m/s in the
speed of sound in seawater section of that Wikipedia article (according to the section above it, the speed of sound in freshwater is almost 1500 m/s). However, the speed of sound in seawater will vary depending mainly on temperature, salinity, and pressure, each of which varies with depth. The figure of 1560 m/s in the text does not address any of those factors, so I would be skeptical about putting it in my notes at all. I personally think most tests would give the specific speed it wants you to use, which would probably be something along the lines of "Assuming an average speed of sound of _____..."
I wasn't really sure what to use, and I dont have an answer key so that also doesn't help me. But I figured I'd use 1560m/s as it was the only speed I found.
sscharter wrote:Hey,
So this is my first time doing this event and I was wondering what is the best way to go about studying...
I have a textbook and I am taking notes on all the information, but would that be enough? Is this the first year the event is using those NGSS practices?
You definitely wanna look up each of the different bullets in the rules packet. (I often use Wikipedia for info, although some may argue with its reliability. A university professor's website may sometimes have good info you can find that). Also, diagrams are extremely helpful. You have 4 sheets so you should be able to put a lot of diagrams. Occasionally you may end up having a diagram on the test that is the exact one in your notes, and it makes those questions rather easy. Random facts (e.g. what is the deepest part of the ocean? The Challenger Deep in the Mariana Trench) can also be important. After you do that, I'd say take practice tests. There are 2 under "Test Exchange" and I'd suggest taking both. If you don't know something look it up, and put it in your note sheets.
If you wanna know how to organize your note sheets, that's a different question, but this is on the information you should have.
Re: Dynamic Planet B/C
Posted: January 3rd, 2015, 12:10 pm
by SOnerd
John Richardsim wrote:sscharter wrote:Hey,
So this is my first time doing this event and I was wondering what is the best way to go about studying...
I have a textbook and I am taking notes on all the information, but would that be enough? Is this the first year the event is using those NGSS practices?
Yeah, textbooks are a good way to go (most of the studying I've done so far has been from a textbook). In addition to textbooks, look around the web for stuff. A couple of other good starting places are the
NOAA Resources and
NOAA Oceans and Coasts.
I've used a lot of web stuff so far. My partner and I have ordered the textbook from Amazon, but it hasn't been delivered yet.
If you're looking for links by topic, you could try clicking the link on this webpage:
http://soinc.org/dynamic_planet_b that says "List of Web Links for 2015 Dynamic Planet". It has a word doc with a bunch of good websites.
Re: Dynamic Planet B/C
Posted: January 7th, 2015, 4:04 pm
by JT016
Salinity:
I know the oceans near the equator are more saline due to increased evaporation and the lack of glaciers provide fresh water, but are there any other important reasons I'm missing? Also, are there any specific areas that would be good to know, in terms of salinity? I read
HEREthat the salinity of the Batlic Sea is about 10ppt. Would that be good to know? If so, are there other places like the Baltic Sea (or areas that are really saline)?
Re: Dynamic Planet B/C
Posted: January 7th, 2015, 6:11 pm
by John Richardsim
JT016 wrote:Salinity:
I know the oceans near the equator are more saline due to increased evaporation and the lack of glaciers provide fresh water, but are there any other important reasons I'm missing?
Well, input of freshwater will also decrease salinity in places, but it can be quite variable (for example, the ITCZ fluctuates in latitude throughout the year, so evaporation is still the primary determinant of salinity at the equator).
JT016 wrote:Also, are there any specific areas that would be good to know, in terms of salinity? I read
HEREthat the salinity of the Baltic Sea is about 10ppt. Would that be good to know? If so, are there other places like the Baltic Sea (or areas that are really saline)?
Well, it certainly can't hurt to know things like that, although from my understanding tests should focus more on WHY an area like the Baltic Sea has such a low salinity, or why an area with a very high salinity has a high salinity (the key word in this sentence is should; I certainly can't guarantee that every test you come across will be written with this mind-set).
Re: Dynamic Planet B/C
Posted: January 8th, 2015, 8:50 am
by bobbuilder
do you need to know a lot of mathematical equation. And are you allowed to bring anything in other than a pencil, calculator and 4 pages of cheat sheet