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HAZUS99 Hawaii and Seismology:
Attenuation |
Epicenter |
HAZUS99 Hawaii |
Magnitude |
Modified Mercalli Intensity |
Munson & Thurber Hawaii |
Peak Ground Acceleration|
Spectral Acceleration
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By Table/Map:
Building Related Losses |
Casualty Estimates 3 Table |
Communication Damage Map |
Debris Generated |
Earthquake Scenario Parameters |
Essential Facilities Damage Table |
Expected Building Damage by Occupancy Table |
Households Without Utilities |
Peak Ground Acceleration and Bridge Damage Map |
Power Station Damage Map |
School Availability/Shelter Needs Map |
Shaking Intensity Overview Map |
Transportation Damage Table |
Utilities Facility Damage Table
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Definitions and Explanation - HAZUS99 Hawaii and Seismology
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HAZUS99 used by Hawaii State Civil Defense
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Through a series of studies beginning in 2000, the HAZUS 99 software Hawaii
database was customized and validated to incorporate Hawaii and Maui
County-specific building inventories, code adoption and enforcement policy
histories of each county, geospatial and soil type information GIS layers,
seismological and attenuation parameters, building damage functions, and
construction cost data parameters. The implementation and testing of these
parameters was carried out under the technical supervision of the Hawaii
State Earthquake Advisory Committee. Sensitivity and validation analyses
were performed utilizing historical earthquake events of various magnitudes
and seismic source regions, in order to compare results with recorded data
and historical accounts. In 2003, HAZUS Data Products utilizing this customized
model were developed, and in 2004, further studies to quantify loss reductions
and the mitigation effectiveness of seismic retrofit, code adoption and
enforcement policies, and to construct a HAZUS Atlas (this product) consisting
of possible credible earthquake scenarios were carried out.
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Attenuation
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The decrease in ground shaking with distance from the earthquake source.
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Attenuation Relation
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Mathematical expression describing the attenuation in ground shaking
(peak ground acceleration or spectral acceleration) with distance from the
earthquake source. The rate of decay depends on the type of fault motion,
the rock types between the source and where you are measuring the effects,
the earthquake's depth and magnitude, and the path the seismic waves take.
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Munson & Thurber Hawaii
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Mathematical expression published in 1997 using earthquakes in Hawaii to
describe the expected variation in ground shaking (peak ground acceleration,
PGA) with earthquake magnitude and site rock type, and the attenuation of
PGA with distance from the earthquake source.
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Epicenter
(http://earthquake.usgs.gov/image_glossary/epicenter.html)
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Magnitude
(http://neic.usgs.gov/neis/general/so_many_magnitudes.html)
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Earthquake size, as measured by the Richter Scale is a well known, but not
well understood, concept. What is even less well understood is the
proliferation of magnitude scales and their relation to Richter's original
magnitude scale. The idea of a logarithmic earthquake magnitude scale was
first developed by Charles Richter in the 1930's for measuring the size of
earthquakes occurring in southern California using relatively high-frequency
data from nearby seismograph stations. This magnitude scale was referred to
as ML, with the L standing for local. This is what was to eventually become
known as the Richter magnitude. As more seismograph stations were installed
around the world, it became apparent that the method developed by Richter
was strictly valid only for certain frequency and distance ranges. In order
to take advantage of the growing number of globally distributed seismograph
stations, new magnitude scales that are an extension of Richter's original
idea were developed. These include body-wave magnitude, mb, and surface-wave
magnitude, MS. Each is valid for a particular frequency range and type of
seismic signal. In its range of validity each is equivalent to the Richter
magnitude.
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Moment Magnitude
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Because of the limitations of all three magnitude scales, ML, mb, and MS,
a new, more uniformly applicable extension of the magnitude scale, known
as moment magnitude, or MW, was developed. In particular, for very large
earthquakes moment magnitude gives the most reliable estimate of earthquake
size. New techniques that take advantage of modern telecommunications have
recently been implemented, allowing reporting agencies to obtain rapid
estimates of moment magnitude for significant earthquakes.
Since January 2002, the U.S. Geological Survey has been reporting moment
magnitudes in reference to the size of earthquakes. The moment magnitude
scale was developed to yield much the same results as the earlier magnitude
scales such as ML (local magnitude), MS (surface-wave magnitude), and Mb
(body-wave magnitude). The two main features of the moment magnitude scale
that make it superior to the earlier ones are: (1) moment magnitude measures
a physical property of the earthquake source, and (2) moment magnitude
accurately measures the size of large earthquakes relative to small
earthquakes. In most cases, moment magnitude is measurable nearly immediately,
thanks to the advent of modern seismometers, digital recording, and real-time
communication links. For all future earthquakes, the USGS will report, if
available and as soon as possible, moment magnitude as the earthquake magnitude.
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Modified Mercalli Intensity Scale
(http://neic.usgs.gov/neis/general/mercalli.html)
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The effect of an earthquake on the Earth's surface is called the intensity.
The intensity scale consists of a series of certain key responses such as
people awakening, movement of furniture, damage to chimneys, and finally
total destruction. Although numerous intensity scales have been developed
over the last several hundred years to evaluate the effects of earthquakes,
the one currently used in the United States is the Modified Mercalli (MM)
Intensity Scale. It was developed in 1931 by the American seismologists
Harry Woodand and Frank Neumann. This scale, composed of 12 increasing
levels of intensity that range from imperceptible shaking to catastrophic
destruction, is designated by Roman numerals. It does not have a mathematical
basis; instead it is an arbitrary ranking based on observed effects. The
Modified Mercalli Intensity value assigned to a specific site after an
earthquake has a more meaningful measure of severity to the non-scientist
than the magnitude because intensity refers to the effects actually experienced
at that place.
The maximum observed intensity generally occurs near the epicenter. The
lower numbers of the intensity scale generally deal with the manner in which
the earthquake is felt by people. The higher numbers of the scale are based
on observed structural damage. Structural engineers usually contribute
information for assigning intensity values of VIII or above. The following
is a description of the 12 levels of Modified Mercalli Intensity
(USGS Hawaiian Volcano Observatory):
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I.
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Not felt. Marginal and long-period effects of large earthquakes.
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II.
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Felt by persons at rest, on upper floors, or favorably placed.
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III.
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Felt indoors. Hanging objects swing. Vibration like passing of light
trucks. Duration estimated. May not be recognized as an earthquake.
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IV.
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Hanging objects swing. Vibration like passing of heavy trucks; or
sensation of a jolt like a heavy ball striking the walls. Standing
cars rock. Windows, dishes, door rattle. Glasses clink. Crockery
clashes. In the upper range of IV, wooden walls and frame creak.
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V.
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Felt outdoors; direction estimated. Sleepers awakened. Liquids
disturbed, some spilled. Small unstable objects displaced or upset.
Doors swing, close, open. Shutters, pictures move. Pendulum clocks
stop, start, change rate.
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VI.
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Felt by all. Many frightened and run outdoors. Persons walk unsteadily.
Windows, dishes, glassware broken. Knickknacks, books, etc., off
shelves. Pictures off walls. Furniture moved or overturned. Weak
plaster and masonry D cracked. Small bells ring (church, school).
Trees, bushes shaken visibly, or heard to rustle.
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VII.
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Difficult to stand. Noticed by drivers. Hanging objects quiver.
Furniture broken. Damage to masonry D, including cracks. Weak chimneys
broken at roof line. Fall of plaster, loose bricks, stones, tiles,
cornices, also unbraced parapets and architectural ornaments. Some
cracks in masonry C. Waves on ponds, water turbid with mud. Small
slides and caving in along sand or gravel banks. Large bells ring.
Concrete irrigation ditches damaged.
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VIII.
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Steering of cars affected. Damage to masonry C; partial collapse.
Some damage to masonry B; none to masonry A. Fall of stucco and some
masonry walls. Twisting, fall of chimneys, factory stacks, monuments,
towers, elevated tanks. Frame houses moved on foundations if not
bolted down; loose panel walls thrown out. Decayed piling broken off.
Branches broken from trees. Changes in flow or temperature of springs
and wells. Cracks in wet ground and on steep slopes.
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IX.
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General panic. Masonry D destroyed; masonry C heavily damage, sometimes
with complete collapse; masonry B seriously damaged. General damage
to foundations. Frame structures, if not bolted, shifted off foundations.
Frames racked. Serious damage to reservoirs. Underground pipes broken.
Conspicuous cracks in ground. In alluviated areas, sand and mud ejected,
earthquake fountains, sand craters.
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X.
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Most masonry and frame structures destroyed with their foundations.
Some well- built wooden structures and bridges destroyed. Serious
damage to dams, dikes, embankments. Large landslides. Water thrown
on banks of canals, rivers, lakes, etc. Sand and mud shifted horizontally
on beaches and flat land. Rails bent slightly.
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XI.
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Rails bent greatly. Underground pipelines completely out of service.
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XII.
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Damage nearly total. Large rock masses displaced. Lines of sight and
level distorted. Objects thrown into the air.
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Peak Ground Acceleration
(http://earthquake.usgs.gov/faq/meas.html#14)
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Acceleration is the rate of change in velocity of the ground shaking (how
much the velocity changes in a unit time), just as it is the rate of change
in the velocity of your car when you step on the accelerator or put on the
brakes. Velocity is the measurement of the speed of the ground motion.
Displacement is the measurement of the actual changing location of the ground
due to shaking. All three of the values can be measured continuously during
an earthquake. The peak ground acceleration (PGA) is the largest acceleration
recorded by a particular station during an earthquake.
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Spectral Acceleration
(http://earthquake.usgs.gov/image_glossary/spectral_accel.html)
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PGA (peak acceleration) is what is experienced by a
particle on the ground. SA (spectral acceleration) is approximately what
is experienced by a building, as modeled by a particle on a massless
vertical rod having the same natural period of vibration as the building.
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Definitions and Explanation by Table / Map
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Building Related Losses
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Structural: Replacement cost of damage done to building structures.
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Nonstructural: Replacement cost of damage done to architectural, mechanical,
and/or electrical components of the buildings.
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Business Interruption Loss: Estimated losses due to the inability of a
business to continue. Cost of wages, loss of income, cost of new rental,
cost of inventory relocation
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Casualty Estimates 3 Table
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Occupancy Load: Population of an area.
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Residential: Population at home.
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Non-Residential: Population at work or at places of business.
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Commute: Population on the road.
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Communication Damage / Power Station Damage Maps
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Functionality
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Day 0: Day of the event.
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50 - 100%: Facility is working at 50% to 100% capacity.
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0 - 50%: Facility is working at 0% to 50% capacity - below acceptable levels.
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Debris Generated
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Debris: The debris shown in HAZUS is from structural building damage
only. It is divided into two categories small (glass, brick, wood, etc)
and large (reinforced concrete or steel). Debris generation is based on:
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Unit weight of structural and nonstructural elements (tons per 1000
sq. ft. of floor area) for each of the model building types.
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Probability of damage states for structural and nonstructural elements
per census tract.
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Square footage of each of the model building types by census tract.
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Debris generated from different damage states of structural and
nonstructural elements (% of unit weight of element).
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Earthquake Scenario Parameters
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Rupture Length: Length of surface fault caused by earthquake event.
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Rupture Orientation: Direction in which the fault is facing.
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Essential Facilities Damage Table
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Moderate: Large cracks in walls, loss of power, potential loss of
back up power, potential damage to any storage tanks not anchored.
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Complete Damage: Building shift off of foundations, potential to
collapse, loss of power and utilities, potential leakage of any tanks.
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Functionality: Facilitys ability to function at 50% or greater
capacity after event.
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Expected Building Damage by Occupancy Table
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Damage Categories
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None: No damage.
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Slight: Cracks in plaster.
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Moderate: Visible large cracks in walls; possible weld cracking in
some building types.
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Extensive: Foundations may be shifted; columns and partial ceiling
collapse; partial building collapse.
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Complete: Building collapse.
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Building Damage Categories
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Residential: Single Family Dwellings, Mobile Homes, Multi Family
Dwellings, Temporary Lodging, Institutional Dormitory, Nursing Home.
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Commercial: Retail Trade, Wholesale Trade, Personal and Repair
Services, Professional/Technical Services, Banks, Hospitals Medical
Office/Clinic; Entertainment & Recreation; Theaters; Parking.
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Industrial: Heavy, Light, Food/Drugs/Chemicals, Metal/Minerals
Processing, High Technology, Construction.
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Agriculture: Agriculture.
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Religion: Church/Non-profit.
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Government: General Services, Emergency Response.
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Education: Grade School, Colleges/Universities.
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Households Without Utilities
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Household: Census 2000 definition 2.92 persons per household.
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Peak Ground Acceleration and Bridge Damage Map
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Extensive: Shear failure of support column without collapse,
significant movement at support connections, major settlement, and
vertical offset.
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Complete: Column collapse and connection losing all bearing
support, tilting of substructure due to foundation failure.
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School Availability/Shelter Needs Map
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Shelter Damage Available: Shelters with moderate or less damage
still structurally usable as housing for displaced households.
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Shelter Damage Unavailable: Shelters with extensive or complete
damage structurally unstable.
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Displaced Households: Households who have been displaced from their
residence.
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Shaking Intensity Overview Map
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See definition for Modified Mercalli Intensity Scale.
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Transportation Damage Table
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Moderate Damage: Moderate damage to building structures, potential
leakage of unanchored fuel tanks, potential damage to back up generators,
moderate settlement of roadways and runways, moderate cracking of support
columns of bridges, loss of commercial power.
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Complete Damage: Building and bridge collapse, major settlement
(few feet) of the roadways and runways, extensive damage to fuel stations.
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Functionality: Facilities still able to continue after event.
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Utilities Facility Damage Table
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Moderate
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For water treatment plants: Malfunction of plant for about a week
due to loss of electric power and backup power, extensive damage to various
equipment, damage to sedimentation basins, damage to chlorination tanks
with no loss of contents, or damage to chemical tanks. Loss of water
quality is imminent.
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For substations: Failure of 40% of disconnect switches or 40% of
circuit breakers, or failure of 40 % of current transformers or by the
building being in moderate damage state.
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For power distribution circuits: Failure of 12% of circuits.
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For generation plants: Chattering of instrument panels and racks,
considerable damage to boilers and pressure vessels, or by the building
being in moderate damage state.
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For communication facilities: Moderate damage to facilities, few
digital switching boards dislodged, or central office out of service for
a few days due to loss of electric power and backup power.
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Complete Damage
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For water treatment plants: Complete failure of all piping, or
extensive damage to the filter gallery.
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For substations: Failure of all disconnect switches, all circuit
breakers, all transformers, or all current transformers, or by the
building being in complete damage state.
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For power distribution circuits: Failure of 80% of all circuits.
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For generation plants: Defined by extensive damage to large
horizontal vessels beyond repair, extensive damage to large motor operated
valves, or by the building being in complete damage state.
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For communication facilities: Complete damage to the building or
damage beyond repair to digital switching boards.
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