Geology Lab Exam 3

What is the hydraulic gradient of the confined aquifer from one well to the other?

.08

The elevation of the water table on the left side of the figure is 250 ft. The elevation of the hydraulic head in Well 1 is 300 ft. What is the vertical hydraulic gradient through the aquitard?

.45

The hydraulic conductivity of the clay is 0.1 m/yr, and the porosity of the clay is 25% (0.25). What is the velocity of the water seeping through the clay aquitard in ft/yr?

.594 ft/yr

A ratio scale of 1:1000 on a topographic map indicates that

1 unit on the map equals 1000 units in the real world

On a map with a scale of 1:24000, what would the ground distance be if the map distance is 5 inches?

1.89 miles

How long in years does it take for the water to seep all the way through the clay aquitard?

185

During the past 99 years, what year you saw the greatest flood on the Flint River at Montezuma?

1994

A 50-year flood is one that has a _______ chance of occurring every year

2%

What is the percent grade of a hill with a gradient of 135 ft/mile?

2.6%

What is the contour interval of the figure?

20

What was the elevation of the Flint River during that greatest flood?

290ft

On this map of Cape May provided here (map scale 1:25,617), the historic positions of the coastline, from 1879 to 1994, are shown. Here, beach erosion is clearly occurring along this section of shoreline. The map distance of shoreline that had been eroded from 1932 to 1994 is 1.2 inches measured along the transect A-A' What is the rate of beach erosion (ft/year) between 1932 and 1994?

41.3 ft/year

River discharge is a product of river channel width, depth, and streamflow velocity. If you know a specific river channel cross-section is 27 ft wide and 2.74 m deep, and streamflow velocity is 22 ft/s, what is the river discharge in ft3/s? (Note: 1 m = 3.28 ft)

5338 ft3/s

Calculate the weight fraction of Iron (Fe) in percentage in the mineral hematite. Hematite = Fe2O3. Fe molecular weight = 55.847 g/mole O molecular weight = 15.999 g/mole

70%

Bankfull stage for the Flint River is 270 feet. Therefore, flood stage is any river elevation greater than 270 feet. What is the approximate probability that the Flint River will flood every year?

77%

If the Flint River has a velocity of 0.36 ft/s, and the channel width is approximately 18 ft during bankfull stage, what is the discharge of the river at bankfull stage? (Hints: River channel depth is essentially the difference between the elevation of the river gage station 255 ft and the elevation of its bankfull stage 270 ft.)

97.2 ft3/s

Which of the following areas of the United States are highly susceptible to earthquakes?

All along the Pacific Coast and Central Mississippi River Valley

Which one of the following is an igneous rock?

Basalt

_______ lava is low viscosity, has a temperature of 1200°C, and typically forms _______ volcanoes

Basaltic; shield

Which one of the following minerals is an ore of copper?

Chalcopyrite

Which type of soil would likely cause structural damage to buildings over time due to potential shrinking and swelling?

Clay loam

The circular depression created by pumping is called

Cone of depression

The regular standard change in elevation between any two adjacent contours is known as the

Contour Interval

If you are traveling from one point to another on a topographic map and there are no elevation values on the contour lines, how can you tell if you are moving uphill?

Contour circles get smaller as you move uphill

A set of tick marked circles inside circles on a topographic map indicate a

Depression

Which direction is groundwater flowing vertically through the aquitard near Well 1?

Downward

Topographic high points that separate distinct drainage networks are called____________.

Drainage Divides

Base on the same picture above, what is the direction of flow of the longshore current?

East to West

The headwaters of a river is known as the zone of _____, because the steepest gradients and fastest velocities are found there

Erosion

Bauxite is an ore of hematite

False

Beach drift causes the barrier island inland movement

False

Floridan Aquifer is the primary fresh water source for most of Georgia, including Savannah and Atlanta region

False

Granite is a type of metamorphic rock

False

Groundwater flows in the direction of the smallest gradient

False

Net beach drift is always zigzag along shore while longshore current is always perpendicular to the shoreline

False

River downcutting will continue as long as there is water in the channel

False

The presence of red-colored iron oxide minerals in the soil on Mars suggests that the planet has always had an oxygen-free atmosphere

False

The reddish stains around your kitchen and bathroom drains are the result of your water having a high calcium content

False

The soils underlying upland pine forests contain a thick O-horizon

False

Unlike other parts of the world, saltwater intrusion is not a problem for the Floridan Aquifer system due to the sufficient rainfall we are receiving in Southeast US

False

Water flows faster in the inner side of a meander river bend and erode the inner side of the river bank

False

Clay minerals form from the chemical weathering of which of the following common mineral(s)?

Feldspars

occurs whenever the volume of water flowing in a channel is greater than the channel's storage capacity

Flood

The difference in elevation between two points on a topographic map, divided by the horizontal distance between those two points, and expressed as ft/mile or m/km is called

Gradient

rigid hydraulic structure built from an ocean shore to limit shoreline retreat

Groins

During an earthquake, the amount of ground shaking can vary depending on the material through which the seismic waves are traveling. For example, solid bedrock will experience minimal shaking, while loose sand. mud, and fill will experience great shaking. This phenomenon is called

Ground Amplification

Which one of the following mineral is commonly used as a red pigment?

Hematite

a breakwater constructed to protect or defend a harbor, stretch of coast, or riverbank

Jetties

Floridan Aquifer's productivity contributes to the aquifer formation, which is mostly made of

Karstic limestone

What poses the greatest hazard living next to a shield volcano?

Lava flows that people can outrun, but vegetation and buildings can't

A raised embankment along a river channel, either natural or man-made, that holds back water is called a ________________

Levee

Based on the figure above, which type of soil would be well-drained and generate well-defined soil horizons

Loamy Sand

Which of the following will yield more iron per ton of ore

Magnetite / Fe3O4

Out at the coring sites (Site A and Site B), the sediment core near the creek had a very thick _____

O-Horizon

(1/RI) x 100

Percent Probability

Refers to the proportion of sediment or soil that is composed of void space

Porosity

Which mineral is a major component in glass?

Quartz

(N+1)/M

Recurrence Interval Formula(RI)

Wetlands adjacent to streams, usually on the stream's floodplain, are called _______ wetlands

Riprarian

A sedimentary rock consisting of clay-sized particles is called

Shale

What is a major drawback when using a groin or jetty to stabilize a beach?

The beach on the downstream side erodes

What is the main purpose of a jetty or groin?

To trap sand and sediment carried by the longshore current

A direct result of runoff is soil erosion

True

A river that has been channelized actually has a greater risk of flooding than if the river's natural course had been left unchanged

True

Bricks are commonly made from clay and aggregate

True

During an earthquake, buildings oscillate. If the frequency of this oscillation is close to the natural frequency of the building, resonance may cause much greater damages

True

Increasing urbanization (more roads, buildings, and parking lots) increases surface runoff and also potential flooding

True

Lime is the basic ingredient in cement

True

Removal of vegetation and ground cover will increase the rate of runoff and erosion

True

The term foliation is a textural characteristic of metamorphic rocks

True

Titanium is commonly used to make white pigment

True

(hydraulic Conductivity/porosity)x hydraulic gradient

Velocity

in the upper troposphere can gum up jet engines in flight and may even cause temporary global cooling by reflecting incoming solar radiation

Volcanic Ash

____represents Stream Channel

a. the stream

___represents drainage divide

b. On hill

What generally occurs on the upstream side of groins and jetties?

beach accretion/growth

How are streams indicated on a topographic map?

by contour lines that form V's which point upstream

____represents Unconfined Aquifer

c. Above Aquitard

Mount Rainier in Washington State is a

composite cone (stratovolcano)

Basalt is denser and darker in color than granite because it

contains a high amount of iron

____represents aquitard

d. one in clay

The accuracy of a flood-frequency model (best-fit line on a flood-frequency graph) depends on how many _______ are used to construct the model. The more _______, the more accurate the model

data points

___represents Confined Aquifer.

e. Below Aquitard

Difference in water elevation/distance

hydraulic gradient

Land that contains a significant amount of fallen leaves or other ground litter will likely contain high____

infiltration capacity

A blue line with dashes and dots along it represents a(n)

intermittent stream

are volcanic mudflows that are typically triggered by heavy rainfall in tropical regions or by the melting of glaciers during effusive lava eruptions on stratovolcanoes

lahars

Which direction is groundwater flowing within the confined aquifer?

left to right

A raised embankment along a river channel, either natural or man-made, that holds back flood waters is called a

levee

A very dangerous phenomenon that occurs when seismic waves travel through water-saturated sediment in which the sediment as a whole acts as a fluid, is called

liquefaction

The letters on the figure above represents a unique hydrologic feature name. ________represents water table

m. Goes through all wells

If a fuel spill occurs on the ground near Well 2, and the fuel infiltrates into the unconfined aquifer, will the stream become contaminated with the spilled fuel?

no

In addition to temperature, magma viscosity is also controlled by

silica (SiO2) content

A river's _______ is defined as the height of the water level in the river above some defined zero point, usually sea-level or the river's stream bed

stage

On a topographic map, the closer the contour lines the _______

steeper the slope

Each point along a topographic line has an elevation of

the same as any other point along that line

What type of contour pattern would you expect to see on areas identified as floodplains?

widely-spaced contour lines