Revised 2 / 17 (Monroe 6th ed.)

Introduction to the hydrosphere and surface processes



Water and Magic

Origins of Water

The Hydrologic Cycle

Water and Life

Water in the Atmosphere and the Transfer of Thermal Energy

Regional weather patterns - Pacific Northwest

Water and the Environment


Water and Magic

If there is magic anywhere on Planet Earth, it's in the water

Water is a di-polar molecule

This results from the arrangement of the hydrogen atoms

Meet at a 105° angle across the oxygen

Gives water a slight electrical charge

Surface tension

Water's polarity results in a slight electrical charge

This causes water molecules to be attracted to other water molecules

Basically, water carries with it a glue which it uses to gum up the works

Capillarity: the magic pump (and other spiffy effects)

Water and Gravity

Water is stuff and is therefore subject to the laws of physics - including gravity

Water and energy

Water contains an immense amount of gravitational potential energy

Converted to kinetic energy when the water is allowed to move

Water is a liquid, and therefore free to move

The resulting kinetic energy is used to perform all sorts of work

Transport of sediments to turning electric generators in hydroelectric plants

Water has a relatively high specific heat

DEFINE: heat vs. temperature

A high specific heat means that water changes temperature very slowly

Because of this, any large body of water (like the ocean) tends to act as a "thermal storage unit"

Can be used to store and transfer heat energy (see below)

Also results in moderate climates in coastal areas

All substances can exist in either the solid, liquid, or gaseous (vapor) phase

Changing from one phase to another requires the addition or removal of energy

Ice + heat --> Water + heat --> Steam

Water is the only known substance which can exist in all three states at normal surface temperatures and pressures

Imagine a glass of ice water on a muggy Mississippi afternoon

If this isn't magic, I don't know what is

Water and density

As a substance loses heat energy, molecular motion slows and the atoms come closer together

Results in a higher specific gravity (mass/unit volume)

All known substances abide by this rule, except for water

The density of water does increase as it cools (as it should)

At 4° C the density vs. temperature graph goes the other way

The density actually begins to decrease

This decrease continues until the solid state is achieved (at 0° C)

At this temperature the density vs. temperature graph resumes its normal trace

This "magic" property of water is no small thing

Think of what would happen if ice was more dense than water!

Water and the pH balance

Describe acid/base pH scales

Water has a pH of 7, and is therefore neither (or both) an acid or base

Actually HOH, and both a proton acceptor and donor, so again it's both

Because of this, water is considered a "universal solvent" which will, if given enough time, chemically attack any and all substances

Remember Strickler's 4th Law of GeoFantasy

Magic stuff?

We haven't even started yet

It get's more exciting as we actually begin the study of what water can do


Origins of Water

Water has existed on earth from very early in geologic time

Some of the oldest known rocks were originally deposited as sediments in water

This means the rivers and oceans had to have existed at that time

Originally, scientists thought the earth's water came from the earth itself (called "connate" water)

Usually from volcanic eruptions (some water does come from these sources)

Recent work indicates that some (possibly most) of the water on earth may have arrived from extra-terrestrial sources

Comets - Basically giant snockballs in space

It is assumed that there were more cometary impacts early in earth's history

These led to the addition of massive amounts of water during the early stages of the earth's formation


The Hydrologic Cycle

The overall volume of water on earth, while clearly not static in the long term, can be considered constant at human time scales

However, the spatial distribution of water can and does change

Constantly moving between numerous "temporary storage units"

This movement is called the Hydrologic Cycle (Monroe: Fig. 15-3, pg. 460)

Several important ideas here

Most of the water on earth is the same water that has been here since the earth first formed

However, the spatial distribution of water can and does change constantly

Storage locations include:

The ocean (obviously the largest): 97.2%

1,327,500,000 cubic kilometers

Glacial ice: 2.15%

Groundwater: 0.625%

Lakes: 0.017%

The atmosphere: 0.001%

Streams: 0.0001%

Adds up to 99.9931% of all the available moisture

The remaining 0.0069% is tied up in other minor reservoirs

Organic material - this includes me and you

Cans of Pepsi, Vienna Sausage, Dinty Moore Stew

...and many, many others

The cycle has 4 main parts

Each involves either a change of phase, or the interaction of water and gravity (a change of location)

Evaporation: liquid to vapor

Condensation: vapor to liquid

Precipitation: liquid and gravity

Collection: liquid and gravity

The water is usually purified as it changes phase

This is a REAL GOOD THING, since we tend to mess it up, no matter what phase it's in


Water and Life

The vast majority of life (as we know it) is composed predominantly of water

Estimates range from 60% to over 90%

Star Trek TNG: "Ugly bags of mostly water"

Without a constant and secure water supply, life will not continue

We can live for weeks w/o food

But only a day or so w/o water

Origins of life assumed to be in water

Fossil record clearly indicates that life began in the sea

A relatively constant and stable environment

Only migrated to land after several billion years of evolution

Water at the cellular level is very important

If our cells dehydrate they die (and so do we)

Water imbalances at the cellular level can, and do, occur

Due to exercise, dehydration, freezing, and other factors

This can result in water/salt concentration problems

Can lead to cramping, and ultimately death of the affected cells

As weird as it sounds, if you want to lose weight drink a large amount of water

If your cells are used to getting an ample supply of fluids, they tend to store less (so you have less "water weight")

If your cells are constantly threatened with dehydration, they will tend to stockpile additional water supplies, increasing your weight

In addition, your body needs water to metabolize fat

If you're dry, the fatty foods that you eat cannot be broken down


Water in the Atmosphere and the Transfer of Thermal Energy

The earth's atmosphere:

Nitrogen (78%)

Oxygen (21%)

Trace amounts of several other gasses

Water also occurs in the atmosphere

Commonly in the vapor phase

Amount of water vapor varies greatly, depending on a multitude of factors

The evaporation of water requires the addition of 80 calories of thermal energy per cubic centimeter

This heat energy is robbed from the local environment

Stored in the vapor

This energy remains locked up in the vapor until conditions change and the vapor condenses into the liquid phase

Releasing the energy back into the environment

This addition and loss of energy results in a global energy transfer

Affects our lives, and the earth processes which make life possible (and pleasant). For example...


When our bodies sweat, the water which evaporates from our skin

Obtains the heat energy necessary for the phase change from the skin, cooling our bodies

In comparison, dogs have no sweat glands

That's why they pant so much

All cooling comes from evaporation of water from their tongues

Now, aren't you glad you have sweat glands?

Global energy transfer and temperature moderation

More solar energy is received on earth at the equator than at the poles

DEFINE: Langley

Excess heat energy is used at the equator to evaporate seawater

Winds transfer this energy north and south to mid-latitudes, where it condenses, rains, and gives up the heat to areas which need it

This tends to moderate surface temperatures on earth

If you don't think this is important, try living on Mercury

Temperatures can vary by up to 600°C from sunlight to shadow, and day to night

Adiabatic cooling and rain shadow deserts

Warm, moist marine air masses move onshore and rise up over mountains

Cooled at a rate of 5.5 F° / 1000' of vertical lift (the "dry adiabatic rate")

Cooling continues until the temperature drops to the "dew point" when condensation begins

Above the dew point the temperature drop is reduced to 3.5 F° / 1000' (the "wet adiabatic rate")

Due to the additional heat energy released by the vapor as it condenses back into the liquid phase

As the air mass (which is now dry) descends the far side of the mountain, it heats back up at the dry adiabatic rate, resulting in a warmer and drier air mass on the lee side of the mountain


Regional weather patterns - Pacific Northwest

Been here since the mid-1970s

Always worked hard and hoped for great time off

Noticed 2 things early on

Summer work - hot as blazes for 2 weeks (also very dry)

Then cool down 'til the next heat wave

Maybe even a bit of rain

DIGRESS TO: redwood roof of Selma house

Winter's off - lots of time but also lots of fog

Lived in Grants Pass at several times

Either raining, or cold & foggy

Cold/foggy come in 2 week stretches

This 2 week pattern seems to hold - watch for it

Both summer (hot & dry) & winter (cold & foggy)

Associated with high pressure systems in both cases

As well as relatively low moisture levels in the atmosphere

Talked to National Weather Service meteorologist about this

Confirmed the 2 week pattern for the high pressure systems

Cause is very uncertain - it just happens?

Look what has happened in our area over Christmas / New Year (1997)

Storm after storm leading to an approx. 30 year flood

Then the high settles into the area

Cold and foggy indeed!

Consider this: It really wasn't that cold (it was January, after all)

Lows were in mid-high 20's

It could have been much colder

With the heavy rain and saturated ground (saturated everything!)

What would happen if we'd had a 30 year freeze following the flood?

Relate O'Brien cabin wet/freeze story


Water and the Environment

Climate and severe storms

Flooding in the Rogue Valley

Plugged drains - how, why and what can be done to fix them

Contamination by sewage and other pollutants

Umpqua River - flooded park including outhouses

Almeda Park - outhouses under water

How about septic systems on the floodplain?

Filtration plant and sewer system

How well do we trust water purification

Road damage

Chuckholes in G.P. and not even through the cold part of winter yet

Ruts in I-5 - real bad in Portland area

Mostly from big trucks - can even see double low spot when road is wet

It will take millions to billions to repair the nation's roads

Driving in any climatic weather

Driving in snow - Susie across Page Mountain

Freezing rain in Portland and Columbia Gorge

Dealing w/big trucks and idiots on the highway

Hydroplane problems

Road closure due to slides

Hwy. 199 at Patrick Creek

Slide on Susie's bus trip

South Fork Smith River - needed more than one guy

Banded iron formations

See separate discussion

The Bretz flood (a.k.a. the Missoula Flood)

Evidence for repeated flooding 13,000 to 15,000 years ago

Eastern Washington

A "protruding lobe of the Laurentide Ice Sheet" dammed the Clark Fork River

Created Lake Missoula (Missoula was under 1800 feet of water)

When lake level rose to 0.9 of dam height the dam "floated"

A very significant number related to density

The density of glacial ice is 0.9

Allowed water to seep underneath

Friction melted the ice and enlarged the hole

Imagine the fountain!

At some point the upper portion of the dam collapsed and the lake emptied

Estimated flow 700 million cubic feet per second

Resulted in MAJOR flooding

Called "jokulhlaups" - Icelandic term

After the lake was drained, the ice dam rebuilt and the process began again

Effects downstream were significant

Channeled Scablands - water spreads out

Columbia Gorge: Q=AV

Willamette Valley - 500' to 1000' of water over Eugene!

What about life at that time?

Water pollution is a legitimate concern

But keep your focus on the main target: the air and land

Water cleans itself every time it evaporates and condenses

Contamination due to mineral resources

Natural causes

Yukon massive sulfide - water well indicator

Human caused

Queen of Bronze & Island Mountain mine re-opening

Iron Mountain, California

Only way to stop contamination is to remove all the sulfides

My personal favorite

Tri-State mining district

Nuclear waste disposal

Soviet practices

U.S. - current practices

Lots of small "temporary storage facilities"

Hanford - leaks into Columbia water system?

Studies (c. 1997) indicate the certainty for future contamination on a massive scale

The lower Columbia is in real trouble

Yucca Mountain

Overuse/misuse of land leading to erosion

Topsoil loss is another of the "fatal flaws" awaiting humankind

Weathering and erosion increasing the sedimentation out in the ocean

Will this be noticed by geologists 1 billion years from now?

Over use and contamination of groundwater

Ogalalla Aquifer



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