Welcome to HYD 602Welcome to HYD 602(Also called “Marine Geology for Hydrographers”)(Also called “Marine Geology for Hydrographers”)

2 hours of lecture (14:30 – 16:30) for eight (8) weeks2 hours of lecture (14:30 – 16:30) for eight (8) weeks Some hiatusesSome hiatuses Quick break after the first hourQuick break after the first hour

No labNo lab Schedule: 1 exam and a finalSchedule: 1 exam and a final prerequisites: none, except a broad background in physical prerequisites: none, except a broad background in physical

sciences; sciences; if you find yourself getting lost in some areas, ask or readif you find yourself getting lost in some areas, ask or read geological dictionary is very useful.geological dictionary is very useful.

Intended to be fairly rigorous, but not excruciatingIntended to be fairly rigorous, but not excruciating We will cover some aspects of global climate change if we get time.We will cover some aspects of global climate change if we get time.

I’ll probably tell a few sea stories but I’d rather hear yoursI’ll probably tell a few sea stories but I’d rather hear yours

The BookThe Book

In geology, we are fortunate: In geology, we are fortunate: PT is a “unifying theory” for all geology, including marinePT is a “unifying theory” for all geology, including marine Siebold and Berger is a basic bookSiebold and Berger is a basic book

not much detailnot much detail somewhat currentsomewhat current

Kennett is much better but sadly out of dateKennett is much better but sadly out of date Use this for most of your studyingUse this for most of your studying

Too much information for a 1 hour courseToo much information for a 1 hour course we will try to get through all of the information but we won’t we will try to get through all of the information but we won’t

stick with the book very wellstick with the book very well will modify content as we go along to adjustwill modify content as we go along to adjust Study class notes more than the bookStudy class notes more than the book

PresentationPresentation Must be on a topic in marine geology/geological Must be on a topic in marine geology/geological

oceanographyoceanography Should be pretty specificShould be pretty specific

bad: “Seismic Reflection Profiling” or “magnetic survey”bad: “Seismic Reflection Profiling” or “magnetic survey” good: “Stratigraphy of Blake Plateau from seismic reflection good: “Stratigraphy of Blake Plateau from seismic reflection

profiling”profiling”

topic “should” be pre-approved by emailtopic “should” be pre-approved by email hopefully by the end of Marchhopefully by the end of March I can suggest one if you likeI can suggest one if you like

Presentations on day of final lecture.Presentations on day of final lecture. Presentations should:Presentations should:

Be interestingBe interesting Be informativeBe informative

What is Oceanography?What is Oceanography? While Hydrographers study the sea floor, Oceanographers While Hydrographers study the sea floor, Oceanographers

study the water and things which go on therestudy the water and things which go on there In this course, we'll be looking at the oceans and the seafloorIn this course, we'll be looking at the oceans and the seafloor

container and its contents container and its contents the sea floor and why it looks the way it does.the sea floor and why it looks the way it does. By the time we’re through, you’ll be able to predict what the By the time we’re through, you’ll be able to predict what the

seafloor will look like anywhere in the world.seafloor will look like anywhere in the world. Well, to a first approximation anywayWell, to a first approximation anyway

Geological Oceanography:Geological Oceanography: OceanographyOceanography but from a geological but from a geological

point of viewpoint of view

OceanographyOceanography Still requires Still requires

us to go out us to go out ON the oceanON the ocean

modern modern research research vessels serve vessels serve a variety of a variety of functions, functions, some of which some of which are highly are highly specializedspecialized

Tools of Oceanographic ResearchTools of Oceanographic Research

Remotely Operated Remotely Operated Vehicles (ROV’s) are Vehicles (ROV’s) are replacing submersibles replacing submersibles for some workfor some work cheapercheaper no safety issuesno safety issues no power or duration no power or duration

limitslimits

USM’s ROV!USM’s ROV!(Benthos Openframe)(Benthos Openframe)

DOE PhantomDOE Phantom

Tools of Oceanographic ResearchTools of Oceanographic Research

AUVs (UUVs)AUVs (UUVs) Latest rageLatest rage USM has one like thisUSM has one like this

ISEISE Simrad EM2000Simrad EM2000

AUV: NavigationAUV: Navigation

Navigating underwater prevents GPS fixesNavigating underwater prevents GPS fixes Acoustic nav is all you have:Acoustic nav is all you have:

LBLLBL USBLUSBL DVLDVL Some combination?Some combination?

Inertial nav systems sense motion and integrate over Inertial nav systems sense motion and integrate over timetime Accuracy function of price and durationAccuracy function of price and duration

Precision versus accuracyPrecision versus accuracy One challenge is to return to an exact spotOne challenge is to return to an exact spot Hyrdo challenge is to pinpoint features in absolute Hyrdo challenge is to pinpoint features in absolute

coordinatescoordinates Hard to do with an AUVHard to do with an AUV

ProgressProgress

Site off of S. Carolina coast, “Georgetown Hole”6x2km gridDepths to 240m

Navigational error: 50m in 22 hours

Current and Future Oceanographic ResearchCurrent and Future Oceanographic Research

Satellites allow us to Satellites allow us to look at the ocean:look at the ocean: frequentlyfrequently synoptically (all at synoptically (all at

once)once) independent of independent of

weather*weather* Seawifs: ocean colorSeawifs: ocean color AVHRR: mostly AVHRR: mostly

temperaturetemperature Etc.:Etc.:

AltimetryAltimetry WavesWaves

LIDAR!!LIDAR!!

*except clouds, which give them fits

What is Marine Geology?What is Marine Geology?

Geology = Geo + ologyGeology = Geo + ology Earth + Study ofEarth + Study of

Marine Geology: Marine Geology: study of that portion of the earth covered by waterstudy of that portion of the earth covered by water

character and historycharacter and history 72% of the earth's surface is covered by water. 72% of the earth's surface is covered by water.

The container, not the contents The container, not the contents Most of the terrestrial surface is Most of the terrestrial surface is

composed of composed of sedimentary rocksedimentary rock , , much of this is marine sediments.much of this is marine sediments. No geology without marine geologyNo geology without marine geology

In this course, we’ll do some geology and some oceanographyIn this course, we’ll do some geology and some oceanography they are relatedthey are related can’t understand marine geology without getting into oceanography.can’t understand marine geology without getting into oceanography.

The Rock CycleThe Rock Cycle The origin of a rock determines its properties and compositionThe origin of a rock determines its properties and composition

These 3 These 3 are most are most important important in the in the oceanocean

Ocean MorphologyOcean Morphology If the earth were level, it’d be ~3,000m under water!If the earth were level, it’d be ~3,000m under water! Note: Sea level is arbitraryNote: Sea level is arbitrary

Controlled by the amount of water, not the size/shape of the Controlled by the amount of water, not the size/shape of the basin (mostly…..)basin (mostly…..)

Ocean MorphologyOcean Morphology

Consider some Consider some features:features:

Continental Continental Margin:Margin: ShelfShelf SlopeSlope RiseRise

Physiography of the Ocean Floor Physiography of the Ocean Floor (Cont.)(Cont.) The The continental continental

shelvesshelves are are broad, gently broad, gently sloping plains.sloping plains. Average width Average width

about 60 kmabout 60 km Seaward edge Seaward edge

generally about generally about 130 to 200 m 130 to 200 m water depthwater depth

Physiography of the Ocean Floor Physiography of the Ocean Floor (Cont.)(Cont.)

The The continental continental slopeslope lies lies seaward of the seaward of the shelf break.shelf break. Slope Slope

steepenssteepens

Physiography of the Ocean Floor Physiography of the Ocean Floor (Cont.)(Cont.)

The The continental continental riserise lies at the lies at the base of slope.base of slope. Slope lessens, Slope lessens,

bottom flattensbottom flattens There are thick There are thick

sedimentary sedimentary deposits, 1000s deposits, 1000s of meters thickof meters thick

Deep-Ocean Basins and TrenchesDeep-Ocean Basins and Trenches trenches are very deep; over 7 miles in the Mariana Trenchtrenches are very deep; over 7 miles in the Mariana Trench basins/abyssal plains are major feature; extremely flatbasins/abyssal plains are major feature; extremely flat

Midocean RidgesMidocean Ridges found in nearly all basinsfound in nearly all basins““mid” means middle; that’s where they aremid” means middle; that’s where they are unlike a lake, the ocean is shallowest in its centerunlike a lake, the ocean is shallowest in its center

These features are distributed in a distinct pattern:These features are distributed in a distinct pattern: no trenches in Atlantic; Pacific surrounded by themno trenches in Atlantic; Pacific surrounded by them continuous ridge in nearly all basinscontinuous ridge in nearly all basins otherwise deep basinsotherwise deep basins

Cross Cross SectionsSections

Ocean basins cover more of the earth’s surface than any other Ocean basins cover more of the earth’s surface than any other featurefeature

ridges cover 1/4 of the earthridges cover 1/4 of the earth