Features of the Ocean Basin


hey guys just a quick review of the

ocean basin a lot of people have asked

if I can put a video up showing what the

basic features are of the ocean basin so

here it is remember that test is coming

up soon so knowing these features going

to be really important because we

discussed these features during lab we

had them in lecture these are things

that you should absolutely know alright

let's take a look at this diagram here

and I'm going to concentrate on this

area right here on areas 1 through 4 to

be honest cut now part number 2 we

didn't really talk about they call that

the continental break we didn't really

get there but number 1 let's go ahead

and take this area over here and let's

go ahead and zoom all the way down over

here to the right because this picture

summarizes everything we're going to

talk about this part right here this

flatter part right here that's just

under the oceans this would be like

number 1 in the diagram above this is

your continental shelf

now the continental shelf is simply

defined as the part the shallow

extension of the continents that would

be underwater it's all continental crust

it's all shallow water it's still under

the oceans and it's kind of where you

start to make a transition from being in

land to being into the ocean but really

you're not truly in the ocean yet you're

just kind of that shallow transition

zone now if we go back over here and we

take a look at our diagram we're going

to take a look at number 3 now this

little area right here and let's go

ahead and zoom back in and concentrate

on area number 3 area number 3 is this

part right here this part right here is

called the continental slope now the

continental slope this is a major

transition zone from being in the

continents to being in the oceans this

is we're going to go from continental

cross to oceanic crust it's going to

start to make a transition and where did

that exactly happens depends on where

well I'm be honest which margin you're

talking about so in this diagram I

couldn't tell you where the exactly the

continental crust ends and where the

oceanic crust begins but the point is is

that this is a transition zone between

them and then if we take a look at a

little more detail here we have this

continental rise and I'll put that in a

triangle the continental rise is really

where the ocean truly begins this is

where you're going to find

all your basaltic rocks or all your

oceanic rocks this is also where

sediment from the land is going to wash

off the slope and go down into the ocean

basin I think in the book they talked

about a turbidity currents going ahead

and doing that well if we pan out from

here and we take a look at our bigger

diagram number four right here that

would be your continental rise now the

point is this is that all of these put

together one through four this all makes

up your continental margin where this

guy here number one is the Shelf number

three would be the slope and number four

would be the rise make sure you have

those notes down and then we'll take a

look at the rest of the ocean basin all

right so when we talk about the ocean

basin we're really talking about this

whole part right here this entire thing

the ocean basin is just a generic term

from continental margin to continental

margin and all the features in between

so this whole guy right here is an ocean

basin but the ocean basin has some

features to it it's going to take a look

at some of the flattest parts of the

features now people get this confused a

lot number five right here and number

five right here and number five right

here are all the same thing

those three number 5s are all abyssal

why SS al Plains plai n s and abyssal

plane and like we talked about in class

abyssal Plains are the flattest parts of

the ocean they're essentially

featureless they're not the deepest

parts of the ocean but they really have

nothing going on it's hard for life to

really exist down there and great

abundance because it's so deep within

the ocean sunlight doesn't get down

there very well but there is still life

down there but the main point here is

that these are really the flattest parts

of the ocean alright so let's talk about

the deepest parts of the ocean that

would be number seven right here these

guys here this is the trench the deep

ocean trench and the big thing about

ocean trenches as they formed from

convergence they formed from a

convergent boundary and if we take a

look and zoom in on this diagram down

here on the Left we're going to see that

at work we talked about oceanic crust

subducting underneath another piece of

crust and when that happens we get this

feature right here this little divot or

this pit right were the two pieces of

crust meets where the subduction is

happening this is where the trench will

form and at the trench you'll commonly

get earthquakes and stuff like that we

discussed about all that the melting the

rising of the magma the volcanoes either

on the continents or within the oceans

but the big point here is that these

trenches these form the deepest parts of

the ocean so if we zoom back out and we

take a look here that's why we're

looking at the stuff when we look at

this diagram this feature goes down

lower than anything else in fact this is

also where the lithosphere is the

thinnest the thinnest lithosphere is

found at the oceanic trench the thickest

lithosphere would be found on the

continents on the mountains but this is

where the thinnest little sphere is okay

so let's go ahead now and take a look at

a couple of other features that you find

along the ocean basin one of them is

this guy right here number nine number

nine is a mid-oceanic ridge and I know

it's kind of hard to tell in this

diagram especially since I circled over

it but the top of this feature looks

like this and we talked about

mid-oceanic ridges back when we talked

about plate tectonics we know that these

are divergent boundaries or it trenches

a convergent boundary a mid-oceanic

ridge is a divergent boundary and this

is where oceanic crust is spreading away

from the volcano out towards the edges

of the continents and was a key piece of

evidence that Harry Hammond has used to

prove his idea of plate tectonics

alright let's go ahead and take a look

at number eight number eight is a

seamount now it's hard to tell from this

picture it's either a seamount or it's a

Guyot it's really hard to tell but

they're really similar the only

difference is this here we have a

seamount kind of a rounded or jag

did eroded mountain underneath the water

then a Guyot is very similar except it's

flat-topped and Anatole is very similar

to that where you have a seamount or a

Guyot and it's got a coral ring on top

and that's the big difference so a

seamount is somewhat rounded and a Guyot

is essentially flat and Anatole has that

coral ring along the top and that's the

difference between the three but the

take-home message is this these are all

eroded features found on the basin of

the ocean floor and lastly we have

number 6 over here number 6 is simply an

island and it is a feature of an ocean

basin why because it extends up from the

ocean basin it's not just a little piece

of land floating out there in the middle

of the ocean alright guys so here's a

complete snapshot number one the

continental shelf number three the slope

number four the rise the three of those

things make up a continental margin all

the number fives are abyssal Plains

number six is an island number seven is

a trench number eight would either be a

sea mount or guyot and earned for an

atoll depending if it's rounded flat or

if it has a coral ring number nine is a

mid-oceanic ridge and over here we have

another continental margin we have the

rise the slope and the Shelf leading up

into the continents I hope you found

this review helpful if you have any

questions please feel free to send me a

message on Edmodo or send me an email

one last quick note sorry trenches don't

forget that trenches form from

convergent boundaries and that

mid-oceanic ridges formed from divergent

boundaries and again I hope you found

this video helpful if you have any

questions please feel free to ask me in

class or send me a message on Edmodo