Section 5.4.3: Earthquake...Richter Magnitude Earthquake Effects 2.5 or less Usually not felt, but...

Section 5.4.3: Risk Assessment – Earthquake

DMA 2000 Hazard Mitigation Plan – Allegany County, New York 5.4.3-1 March 2018

5.4.3 Earthquake

This section provides a profile and vulnerability assessment of the earthquake hazard.

5.4.3.1 Hazard Profile

Profile information is provided below (including description, extent, location, previous occurrences and

losses, probability of future occurrences, and impacts of climate change).

Description

An earthquake is sudden movement of the earth’s surface caused by release of stress accumulated within

or along the edge of the earth’s tectonic plates, a volcanic eruption, or a manmade explosion (Federal

Emergency Management Agency [FEMA] 2016, Shedlock and Pakiser 1997). Most earthquakes occur

where the earth’s tectonic plates meet (faults); however, less than 10 percent of earthquakes occur within

plate interiors. New York State (NYS) is in an area where plate interior-related earthquakes occur. As

plates continue to move and plate boundaries change over geologic time, weakened boundary regions

become part of the interiors of the plates. These zones of weakness within the continents can cause

earthquakes from stresses that originate at the edges of the plate or in the deeper crust (Shedlock and

Pakiser 1997).

The location of an earthquake is commonly described by its focal depth and the geographic position of its

epicenter. Focal depth of an earthquake is depth from earth’s surface to the region where an earthquake’s

energy originates (the focus or hypocenter). The epicenter of an earthquake is the point on the earth’s

surface directly above the hypocenter (Shedlock and Pakiser 1997). Earthquakes usually occur without

warning, and their effects can impact areas a great distance from the epicenter (FEMA 2001).

According to the U.S. Geological Survey (USGS) Earthquake Hazards Program, an earthquake hazard is

anything associated with an earthquake that may affect a resident’s normal activities. This includes

surface faulting, ground shaking, landslides, liquefaction, tectonic deformation, tsunamis, and seiches. A

description of each of these is as follows:

• Surface faulting: Displacement that reaches the earth’s surface during slip along a fault. This

commonly occurs with shallow earthquake (epicenter less than 20 kilometers).

• Ground motion (shaking): Movement of the earth’s surface from earthquakes or explosions.

Ground motion or shaking is produced by waves generated by sudden slip on a fault or sudden

pressure at the explosive source; waves then travel through the earth and along its surface.

• Landslide: Movement of surface material down a slope.

• Liquefaction: Process by which water-saturated sediment temporarily loses strength and acts as a

fluid (similar to wiggling your toes in the wet sand near the water at the beach). This effect can be

caused by earthquake shaking.

• Tectonic Deformation: Change in original shape of a material due to stress and strain.

• Tsunami: A sea wave of local or distant origin that results from large-scale seafloor

displacements associated with large earthquakes, major submarine slides, or exploding volcanic

islands.

• Seiche: Sloshing of a closed body of water from earthquake shaking (USGS 2012).



Extent

An earthquake’s magnitude and intensity are used to describe size and severity of the event. Magnitude is

energy released at the source (focus) of the earthquake, and expressed by ratings on the Richter Scale

and/or the moment magnitude scale (MMS). The Richter Scale has no upper limit; however, it is not used

to indicate damage (USGS 2012). Intensity is overall severity of shaking felt during the event. Table

5.4.3-1 lists Richter scale magnitudes and corresponding earthquake effects.

Table 5.4.3-1. Richter Scale

Richter Magnitude Earthquake Effects

2.5 or less Usually not felt, but can be recorded by seismograph

2.5 to 5.4 Often felt, but only causes minor damage

5.5 to 6.0 Slight damage to buildings and other structures

6.1 to 6.9 May cause a lot of damage in very populated areas

7.0 to 7.9 Major earthquake; serious damage

8.0 or greater Great earthquake; can totally destroy communities near the epicenter

Source: Michigan Tech University No Date (n.d.).

The MMS, used to describe size of an earthquake, is based on the seismic moment and applies to all sizes of

earthquakes (USGS 2012d). The Richter Scale is not commonly used anymore—it has been replaced by the

MMS, a more accurate measure of earthquake size (USGS 2012). The MMS uses the following classifications

of magnitude:

• Great—Mw > 8

• Major—Mw = 7.0 - 7.9

• Strong—Mw = 6.0 - 6.9

• Moderate—Mw = 5.0 - 5.9

• Light—Mw = 4.0 - 4.9

• Minor—Mw = 3.0 - 3.9

• Micro—Mw < 3.

Earthquake intensity varies with location. Measurement of intensity of an earthquake is based on

observed effects of ground shaking on people, buildings, and natural features. The Modified Mercalli

(MMI) scale expresses intensity of an earthquake and indicates strength of felt shock at a particular

location. Table 5.4.3-2 summarizes earthquake intensity as expressed by the MMI scale. Table 5.4.3-3

displays the MMI scale and its relationship to peak ground acceleration (PGA) in the area of the

earthquake.

Table 5.4.3-2. Modified Mercalli Intensity Scale

Mercalli Intensity Shaking Description

I Not Felt Not felt except by a very few under especially favorable conditions.

II Weak Felt by only a few persons at rest, especially on upper floors of buildings.

III Weak

Felt noticeably by persons indoors, especially on upper floors of buildings. Many people do not

recognize it as an earthquake. Standing automobiles may rock slightly. Vibrations are similar to those

induced by a passing truck. Duration is estimated.

IV Light Felt indoors by many, outdoors by few during the day. At night, some awakened. Dishes, windows,



Mercalli Intensity Shaking Description

doors disturbed; walls make cracking sound. Sensation like heavy truck striking building. Standing

automobiles rocked noticeably.

V Moderate Felt by nearly everyone; many awakened. Some dishes, windows broken. Unstable objects overturned.

Pendulum clocks may stop.

VI Strong Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage

slight.

VII Very

Strong

Felt by all. Damage negligible in buildings of good design and construction; slight to moderate in well-

built ordinary structures; considerable damage in poorly built or badly designed structures; some

chimneys broken.

VIII Severe

Felt by all. Damage slight in specially designed structures; considerable damage in ordinary substantial

buildings with partial collapse. Damage great in poorly built structures. Fall of chimneys, factory

stacks, columns, monuments, walls. Heavy furniture overturned.

IX Violent

Felt by all. Damage considerable in specially designed structures; well-designed frame structures

thrown out of plumb. Damage great in substantial buildings, with partial collapse. Buildings shifted off

foundations.

X Extreme Felt by all. Some well-built wooden structures destroyed; most masonry and frame structures destroyed

with foundations. Rails bent.

Source(s): USGS 2014.

Table 5.4.3-3. Modified Mercalli Intensity (MMI) and PGA Equivalents

Modified Mercalli Intensity Acceleration (%g) (PGA) Perceived Shaking Potential Damage

I < .17 Not Felt None

II .17 – 1.4 Weak None

III .17 – 1.4 Weak None

IV 1.4 – 3.9 Light None

V 3.9 – 9.2 Moderate Very Light

VI 9.2 – 18 Strong Light

VII 18 – 34 Very Strong Moderate

VIII 34 – 65 Severe Moderate to Heavy

IX 65-124 Violent Heavy

X >124 Extreme Very Heavy

Source: Freeman et al. (Purdue University) 2004.

Note: PGA Peak Ground Acceleration

Seismic hazards are often expressed in terms of PGA and spectral acceleration (SA). USGS defines PGA

and SA as follows: PGA is effect on a particle on the ground, a common earthquake measurement of

maximum ground acceleration during earthquake shaking at a location. SA is approximate effect on a

building, as modeled by a particle mass on a massless vertical rod with the same natural period of

vibration as the building (USGS 2012). Both PGA and SA can be measured in fraction of g (acceleration

due to gravity) or as a percent acceleration due to gravity (%g). Study of geographic areas combined with

an assessment of historical earthquakes allows geologists to determine seismic risk and to create seismic

hazard maps, which show likely PGA or SA values in a region during an earthquake. PGA and SA hazard

maps provide insight into location-specific vulnerabilities (NYS Division of Homeland Security and

Emergency Services [DHSES] 2011).

Since 1948, national maps of earthquake shaking hazards have been produced. These maps provide

information essential to creating and updating seismic design requirements for building codes, insurance

rate structures, earthquake loss studies, retrofit priorities, and land use planning in the United States.

Scientists frequently revise these maps to reflect new information and knowledge. Buildings, bridges,

https://en.wikipedia.org/wiki/Earthquake

https://en.wikipedia.org/wiki/Seismic_risk

https://en.wikipedia.org/wiki/Seismic_hazard_map

https://en.wikipedia.org/wiki/Seismic_hazard_map



highways, and utilities built to meet modern seismic design requirements are typically able to withstand

earthquakes better, with less damages and disruption. After thorough review of studies, professional

organizations of engineers update seismic-risk maps and seismic design requirements specified in

building codes (Brown et al. 2001).

USGS updated the National Seismic Hazard Maps in 2014, which supersede the 2008 and 2002 maps.

New seismic, geologic, and geodetic information regarding earthquake rates and associated ground

shaking were incorporated into these revised maps. The 2014 map represents the best available data as

determined by USGS.

The 2014 Seismic Hazard Map shows that most of Allegany County has a PGA between 0.02g and 0.03g,

and a very small portion of the County (the south/southwest section) has a PGA between 0.01g and 0.02g

(Figure 5.4.3-1). This map is based on peak ground acceleration (g) with 10% probability of exceedance

within 50 years.



Figure 5.4.3-1. Peak Acceleration (%g) with 10% Probability of Exceedance within 50 Years

Source: USGS, 2014

Note: The black circle indicates the approximate location of Allegany County. The figure indicates that the County has a PGA between 0.01 and 0.03g.



The NYS Geological Survey (NYSGS) conducted seismic shear-wave tests of the State’s surficial

geology (glacial deposits). Based on these test results, surficial geologic materials of NYS were

categorized according to the National Earthquake Hazard Reduction Program’s (NEHRP) Soil Site

Classifications (see Table 5.4.3-4 below). The NEHRP developed five soil classifications that affect

severity of an earthquake. The soil classification system ranges from A to E, where A represents hard

rock that reduces ground motions from an earthquake, and E represents soft soils that amplify and

magnify ground shaking, increasing building damage and losses. Figure 5.4.3-2 illustrates NEHRP soil

classifications in NYS, while Figure 5.4.3-3 illustrates NEHRP soil classifications in Allegany County.

Table 5.4.3-4. NEHRP Soil Classifications

Soil Classification Description

A Very hard rock (for example, granite, gneisses; and most of the Adirondack

Mountains)

B Rock (sedimentary) or firm ground

C Stiff clay

D Soft to medium clays or sands

E Soft soil including fill, loose sand, waterfront, lake bed clays

Source: NYS DHSES 2014.



Figure 5.4.3-2. NEHRP Soils in New York


Note: The black circle indicates the approximate location of Allegany County. The figure shows that the County’s NEHRP soil classifications include primarily B soils, with smaller amounts of D and E

soils.



Figure 5.4.3-3. NEHRP Soils in Allegany County




As illustrated in Figure 5.4.3-2 and



Figure 5.4.3-3, soils in Allegany County are primarily NEHRP Soil Classes B, D, and E. In most of the

County, soils are Class B, with small amounts of D soils and very small amounts of E soils.

A probabilistic assessment occurred of the 100-, 500-, and 2,500-year mean return periods (MRP) through

a Level 2 analysis applying the Hazards United States (HAZUS) – MultiHazards (MH), Version 2.2

probabilistic model to analyze the earthquake hazard within Allegany County. A Level 2 HAZUS

analysis evaluates statistical likelihood that a specific event will occur and with what consequences. A

100-year MRP event is an earthquake with 1% chance that mapped ground motion levels (PGA) will be

exceeded in any given year. A 500-year MRP is an earthquake with 0.2% chance that mapped PGAs will

be exceeded in any given year. A 2,500-year MRP is an earthquake with 0.04% chance that mapped

PGAs will be exceeded in any given year

Figure 5.4.3-4 through Figure 5.4.3-6 illustrate geographic distributions of PGAs (g) across Allegany

County for 100-, 500-, and 2,500-year MRP events at the census-tract level.



Figure 5.4.3-4. Peak Ground Acceleration Modified Mercalli Scale for a 100-Year MRP Earthquake Event

Source: HAZUS-MH 3.0.

Note: PGA for the 100-year MRP is 0.88 to 0.96 %g.



Figure 5.4.3-5. Peak Ground Acceleration Modified Mercalli Scale for a 500-Year MRP Earthquake Event


Note: PGA for the 500-year MRP is 2.67 to 3.08%g.



Figure 5.4.3-6. Peak Ground Acceleration Modified Mercalli Scale for a 2,500-Year MRP Earthquake Event


Note: PGA for the 2,500-year MRP is 7.67 to 10.56%g.



Location

As noted in the 2014 NYS HMP, importance of the earthquake hazard in NYS is often underestimated

because other natural hazards (for example, hurricanes and floods) occur more frequently, and because

major hurricanes and floods have occurred more recently than a major earthquake event (NYS DHSES

2011). However, potential for earthquakes exists across all of NYS and the entire northeastern United

States. The New York City Area Consortium for Earthquake Loss Mitigation (NYCEM) ranks NYS as

having the third highest earthquake activity level east of the Mississippi River (Tantala et al. 2003).

Three general regions in NYS have higher seismic risk than other parts of the State: (1) the north and

northeast third of the State, which includes the North Country/Adirondack region and a portion of the

greater Albany-Saratoga region; (2) the southeast corner, which includes the greater New York City area

and western Long Island; and (3) the northwest corner, which includes Buffalo and its surrounding area.

Overall, these three regions are the most seismically active areas of the State, with the north-northeast

portion having the higher seismic risk, and the northwest corner of the State having the lower seismic risk

(NYS DHSES 2014). None of these higher risk areas includes Allegany County.

“Faults” are fractures or fracture zones with rocks on adjacent sides that have broken and moved upward,

downward, or horizontally (Volkert and Witte 2015). Movement can occur at faults and cause an

earthquake. Numerous faults are present throughout NYS, and Figure 5.4.3-7 illustrates faults relative to

Allegany County (New York State Museum 2012). Allegany County falls within the Clarenon-Linden

seismic zone, within which a 7-point seismic disturbance on the Richter scale can occur (although no

instance of an event of that magnitude in this fault has been recorded). The fault’s epicenter lies farther

north on the Wyoming/Genesee County Border, with a small portion jutting into Allegany County at the

Town of Centerville.

The plate boundary closest to the East Coast is the Mid-Atlantic Ridge, approximately 2,000 miles east of

Pennsylvania (PA). More than 200 million years ago, when the continent Pangaea rifted apart forming the

Atlantic Ocean, the northeast coast of America was a plate boundary. At that plate boundary, many faults

formed in the region. Although these faults are geologically old and are contained in a passive margin,

they act as pre-existing planes of weakness and concentrated strain. When a strain exceeds the strength of

the ancient fault, it ruptures, causing an earthquake (PA Department of Conservation and Natural

Resources [DCNR] 2007).



Figure 5.4.3-7. Faults in New York State

Source: New York State Museum, 2012

Note: Allegany County is outlined in yellow.

The Lamont-Doherty Cooperative Seismographic Network (LCSN) monitors earthquakes that occur

primarily in the northeastern United States. Goals of the monitoring project are to compile a complete

earthquake catalog for this region, assess earthquake hazards, and study causes of earthquakes in the

region. LCSN operates 40 seismographic stations in the following seven states: Connecticut, Delaware,

Maryland, New Jersey, NYS, PA, and Vermont. No seismographic stations are within Allegany County;

however, several are in the vicinity of the County. Figure 5.4.3-8 shows locations of these stations in

western NYS (LCSN 2014). Because Allegany County is near the border of the Western New York

Subnetwork, the Western PA and PA/Delaware/Maryland Subnetworks were also checked for proximate

stations; however, none of the stations in these networks is near the NYS border.



Figure 5.4.3-8. Lamont-Doherty Seismic Station Locations in the Western New York State Area

Source: LCSN 2012.

Note: The black oval indicates the approximate location of Allegany County.

In addition to the Lamont-Doherty Seismic Stations, USGS operates a global network of seismic stations

to monitor seismic activity. No USGS seismic stations are within NYS, but Figure 5.4.3-9 shows locations

of USGS seismic stations near NYS.



Figure 5.4.3-9. USGS Seismic Stations near New York State

Source: USGS 2015.


Figure 5.4.3-10 illustrates epicenters of historical earthquakes across the northeast United States and in

NYS that occurred between October 1975 and September 2013. Multiple earthquakes originating outside

NYS’s borders have been felt within the State. According to the NYS HMP, these events are considered

significant for hazard mitigation planning because earthquakes such as those could inflict damage within

the State in certain situations.



Figure 5.4.3-10. Earthquake Epicenters in the Northeast United States, October 1975 to September 2013

Source: USGS 2013.




Previous Occurrences and Losses

Many sources provided historical information on previous occurrences and losses associated with

earthquakes throughout NYS. Therefore, with so many sources reviewed for the purpose of this HMP

update, loss and impact information about many events could vary depending on the source. According to

the NYS Geological Survey and the NYS 2014 HMP update, approximately 36 significant earthquakes

affected NYS between 1737 and 2005. Furthermore, between 1973 and 2012, epicenters of

189 earthquakes were in NYS. Of those 189 earthquakes, none was officially reported in Allegany

County (NYS DHSES 2014). However, two notable earthquakes originating in Canada produced tremors

in NYS reaching 5.0 or greater magnitudes—one in western NYS on June 23, 2010, and the other in

northern NYS on May 17, 2013 (NYS DHSES 2014). According to the sources reviewed, Allegany

County residents felt the 2010 earthquake; whether Allegany County residents felt the 2013 earthquake

cannot be confirmed.

Between 1954 and 2016, NYS was included in one earthquake-related major disaster declaration (DR) or

emergency declaration (EM). Generally, these disasters cover a wide region of the State; therefore, they

may have impacted many counties. However, not all counties were included in the DR. Allegany County

was not included in any DRs or EMs (FEMA 2016).

For this 2018 HMP Update, earthquakes events were summarized from 1929 to 2016 (see Table 5.4.3-5

below). Based on all sources researched, no known earthquake events occurred within Allegany County

and its municipalities between 1929 and 2016, although up to 10 earthquakes may have impacted

Allegany County within that same time span. Not all sources have been identified or researched;

therefore, other events may have occurred throughout the County and region. Earthquakes with epicenters

in neighboring counties have been included in Table 5.4.3-5, as these likely were felt in Allegany County,

although damages may have been minimal or nonexistent.


DMA 2000 Hazard Mitigation Plan Update – Allegany County, New York 5.4.3-20 March 2018

Table 5.4.3-5. Earthquake Events in Allegany County, 1929 to 2016

Dates of Event Event Type and

Magnitude

(Richter Scale)

Location FEMA

Declaration

Number

County

Designated?

Losses / Impacts

August 12, 1929 Earthquake

5.2 Attica, NY N/A N/A

250 chimneys fell, brick buildings damaged, Attica prison walls, wells

went dry (regional impacts).

January 1, 1966 Earthquake

4.7 Attica, NY N/A N/A Chimneys and walls damaged (regional impacts).

June 13, 1967 Earthquake

3.9 Attica, NY N/A N/A Chimneys and walls damaged (regional impacts).

1986 Earthquake

N.G. Unknown N/A N/A

No reference and/or no damage reported. Felt by residents in Allegany

County.

May 12, 2008 Earthquake

2.3 Attica, NY N/A N/A No reference and/or no damage reported.

December 23, 2008 Earthquake

2.1 Caldonia, NY N/A N/A No reference and/or no damage reported.

June 5, 2009 Earthquake


September 23, 2009 Earthquake


Jun. 23, 2010 Earthquake

5.0

Centered north of

Ottawa, Canada

N/A No A magnitude-5.0 earthquake struck at the Ontario-Quebec border region

of Canada, shaking homes and businesses from Toronto to the States of

New York, Michigan, and Vermont, according to USGS. The earthquake

was centered at depth of about 12 miles.

Allegany County residents reported feeling this earthquake.

March 23, 2012 Earthquake

2.5 Mt. Morris, NY N/A N/A No reference and/or no damage reported.

Source(s): FEMA 2016, IRIS 2016, Livingston County HMP 2015, NYS DHSES 2014, USGS 2016.

Notes:

All magnitudes referenced refer to the Richter Scale,unless otherwise specified.

DHSES Department of Homeland Security and Emergency Services IRIS Integrated Risk Information System NYS New York State FEMA Federal Emergency Management Agency N/A Not applicable USGS U.S. Geological Survey

HMP Hazard Mitigation Plan N.G. Not Given



Probability of Future Events

Earthquake hazard maps illustrate distributions of earthquake shaking levels with certain probabilities of

occurrence over a given time period. According to USGS, in 2014 (the date of the most recent analysis),

Allegany County had a PGA of 0.01 to 0.0.3g for earthquakes with 10-percent probability of occurrence

within 50 years.

NYS DHSES indicates that the earthquake hazard in NYS is often understated because other natural

hazards occur more frequently (such as hurricanes, tornadoes, and flooding), and are much more visible.

However, potential for earthquakes exists across the entire northeastern United States, including NYS and

Allegany County (NYS DHSES 2011).

Earlier in this section, the identified hazards of concern for Allegany County were ranked. NYS DHSES

conducts a similar ranking process for hazards that affect the State. Probability of occurrence or

likelihood of event is one parameter used for ranking hazards. Based on historical records and input from

the Planning Partnership, probability of earthquake occurrence in the County is considered “Frequent”

(likely to occur within 25 years). Despite no known occurrences of earthquakes within Allegany County,

and few reports of earthquakes affecting Allegany County, some direct and indirect impacts on the

County from future earthquakes are expected that may affect the general building stock and local

economy, and may induce secondary hazards such as ignition of fires and utility failures. Table 5.4.3-6

below lists probabilities of future earthquakes affecting the County, based on historical data.

Table 5.4.3-6. Probabilities of Future Occurrences of Earthquake Events

Hazard Type

Number of Occurrences

Between 1929 and 2016

Rate of Occurrence

or Annual Number

of Events (average)

Recurrence Interval (in years) (# Years/Number

of Events)

Probability of Event in any given year

% chance of occurrence in any

given year

Earthquake with epicenter

inside County 0 0 N/A 0.00 0.00%

Earthquakes felt by the

County (including those

with epicenters outside the

County)

10 0.01 8.7 0.11 11.49%

Source: FEMA 2016, IRIS 2016, Livingston County HMP 2015, NYS DHSES 2014, USGS 2016.

Notes:

DHSES Department of Homeland Security and Emergency Services N/A Not applicable

IRIS Integrated Risk Information System NYS New York State FEMA Federal Emergency Management Agency USGS U.S. Geological Survey

HMP Hazard Mitigation Plan

Impacts of Climate Change

Providing projections of future climate change for a specific region is challenging. Shorter term

projections are more closely tied to existing trends, rendering longer term projections even more

challenging. The further into the future a prediction extends, the more subject to changing dynamics it

becomes. Potential impacts of global climate change on earthquake probability are unknown. Some

scientists feel that melting glaciers could induce tectonic activity. As ice melts and water runs off,

tremendous amounts of weight are shifted on the earth’s crust. As newly freed crust returns to its original,



pre-glacier shape, it could cause seismic plates to slip and stimulate volcanic activity, according to

research into prehistoric earthquakes and volcanic activity. National Aeronautics and Space

Administration (NASA) and USGS scientists found that retreating glaciers in southern Alaska might be

opening the way for future earthquakes.

Secondary impacts of earthquakes could be magnified by future climate change. Soils saturated by

repetitive storms could liquify during seismic activity. Dams storing increased volumes of water because

of changes in flow rates could fail during seismic events. Currently, no models are available to estimate

these effects.

5.4.3.2 Vulnerability Assessment

To understand risk, a community must evaluate what assets are exposed or vulnerable to the identified

hazard. Because the entire County is exposed to the earthquake hazard, all assets in Allegany County

(population, structures, critical facilities, and lifelines), as described in the County Profile (Section 4), are

vulnerable. The following section includes an evaluation and estimation of potential impacts of the

earthquake hazard on Allegany County, including the following:

• Overview of vulnerability

• Data and methodology used for the evaluation

• Impacts on (1) life, safety, and health of residents; (2) general building stock; (3) critical

facilities; (4) economy; and (5) future growth and development

• Effect of climate change on vulnerability

• Change of vulnerability as compared to that presented in the 2011 Allegany County Multi-

Jurisdictional HMP

• Further data collection that will increase understanding of this hazard over time.

Overview of Vulnerability

Earthquakes usually occur without warning and can impact areas a great distance from their points of

origin. Extent of damage depends on density of population and building and infrastructure construction in

the area shaken by the earthquake. Some areas may be more vulnerable than others because of soil type,

ages of buildings, and building codes in place. Compounding potential for damage is that, historically,

Building Officials Code Administration (BOCA) regulations in the northeast states were developed to

address local concerns, including heavy snow loads and wind—seismic requirements for design criteria

are not as stringent as those of the west coast of the United States, which relies on the more seismically

focused Uniform Building Code. As such, a smaller earthquake in the northeast can cause more structural

damage than if it would occur in the west.

The entire population and general building stock inventory of the County is at risk of damage or loss due

to impacts of an earthquake. Potential losses associated with earth shaking were calculated for Allegany

County from three probabilistic earthquake events: the 100-year, 500-year, and 2,500-year mean return

periods (MRP). Effects on population, existing structures, critical facilities, and the economy within

Allegany County are presented below, following a summary of data and methodology used.



Data and Methodology

A probabilistic assessment occurred of 100-, 500- and 2,500-year MRPs applying HAZUS-MH to analyze

the earthquake hazard and provide a range of loss estimates for Allegany County. The probabilistic

method involves absorption of information about historical earthquakes and inferred faults, locations, and

magnitudes, and computations (by census tract) of probable ground shaking levels that may occur during

a recurrence period. According to NYCEM, probabilistic estimates are best for urban planning, land use,

zoning, and seismic building code regulations (NYCEM 2003). The default assumption is a magnitude

7.0 earthquake for all return periods. In addition, an annualized loss run was conducted via HAZUS-MH

to estimate annualized general building stock dollar losses in Allegany County.

Ground shaking is the primary cause of earthquake damage to manmade structures, and soft soils amplify

ground shaking. One contributor to site amplification is velocity at which rock or soil transmits shear

waves (S-waves). NEHRP developed five soil classifications according to shear-wave velocity that affect

severity of an earthquake. The soil classification system ranges from A to E, whereby A represents hard

rock that reduces ground motions from an earthquake and E represents soft soils that amplify and magnify

ground shaking, increasing building damage and losses. Soils in Allegany County are NEHRP Soil

Classes A through E, or very hard rock to soft soils.

Figure 5.4.3-3 illustrates NEHRP soil classifications in Allegany County. According to NYCEM, soft soils

(NEHRP Soil Classes D and E) can amplify ground shaking to damaging levels even during a moderate

earthquake (NYCEM 2003).

Data from the local soil map was entered into HAZUS-MH 3.0 to replace default soil conditions. These

data updates allowed for a Level 2 earthquake analysis. Groundwater was set at depth of five (5) feet

(default setting). Damage and loss due to liquefaction, landslide, or surface fault rupture were not

included in this analysis.

In addition to the probabilistic scenarios cited, a loss run was conducted via HAZUS MH to estimate

annualized general building stock dollar losses in the County. The loss methodology combines estimated

losses associated with ground shaking for eight return periods: 100-, 250-, 500-, 750-, 1,000-, 1,500-,

2,000-, and 2,500-year, which are based on values from USGS seismic probabilistic curves. Annualized

losses are useful for mitigation planning because they provide a baseline from which to (1) compare risk

from one hazard across multiple jurisdictions and (2) compare degree of risk from all hazards in each

participating jurisdiction.

As noted in the HAZUS-MH Earthquake User Manual: “Uncertainties are inherent in any loss estimation

methodology. They arise in part from incomplete scientific knowledge concerning earthquakes and their

effects upon buildings and facilities. They also result from the approximations and simplifications that are

necessary for comprehensive analyses. Incomplete or inaccurate inventories of the built environment,

demographics and economic parameters add to the uncertainty. These factors can result in a range of

uncertainly in loss estimates produced by the HAZUS Earthquake Model, possibly at best a factor of two

or more.” However, HAZUS’ potential loss estimates are acceptable for the purposes of this HMP.

Occupancy classes available in HAZUS-MH were condensed into categories of residential, commercial,

industrial, agricultural, religious, government, and educational to facilitate the analysis and presentation

of results. Residential loss estimates were calculated for both multi-family and single family dwellings.

Impacts on critical facilities and utilities were also evaluated.



All exposure and loss estimates discussed in the assessment below pertain to Allegany County. HAZUS-

MH 3.0 generates results at the U.S. census-tract level. Boundaries of census tracts are not always

coincident with town and village boundaries in Allegany County. Results in the tables below are listed for

census tracts, with associated towns and villages listed for each tract. Figure 5.4.3-11 shows spatial

relationships between census tracts and town and village boundaries.



Figure 5.4.3-11. Hazus-MH Census Tracts in Allegany County

Source: Hazus-MH 3.0.



Impacts on Life, Health, and Safety

Overall, the entire population of Allegany County is exposed to an earthquake event. According to the

2010 U.S. Census, Allegany County had a population of 48,946 people. Impacts of an earthquake on life,

health, and safety depend on severity of the event. Risk to public safety and loss of life from an

earthquake in the County is minimal. However, a higher risk to public safety is posed within interiors of

buildings from structural damage or people walking below building ornamentation and chimneys that

may be loose and fall as a result of an earthquake.

Populations considered most vulnerable are within the built environment, particularly near unreinforced

masonry construction. In addition, the vulnerable population includes the elderly (persons over age 65)

and individuals living below the census poverty threshold. These socially vulnerable populations are most

susceptible, based on a number of factors including their lower physical and financial ability to react or

respond during a hazard, and locations and construction quality of their housing.

An exposure analysis occurred, based on NEHRP soils data and 2010 U.S. Census population data. As

noted earlier, NEHRP soil classes D and E can amplify ground shaking to damaging levels even during a

moderate earthquake, and thus increase risk to the population. Populations within municipalities on

NEHRP Class D and E soils were calculated, and are listed in Table 5.4.3-7 below. Overall, approximately

21.2-percent of the County’s population is located on NEHRP Class D and E soils.

Table 5.4.3-7. Approximate Populations on NEHRP "D" and "E" Soils

Municipality Total Population

(2010 U.S. Census)

Population NEHRP Class "D" and "E" Soils

Total Population Exposed

Percent of Population Exposed

Alfred (T) 1,063 0 0.0%

Alfred (V) 4,174 0 0.0%

Allen (T) 448 13 2.9%

Alma (T) 842 0 0.0%

Almond (T) 1,218 57 4.7%

Almond (V) 415 0 0.0%

Amity (T) 1,339 323 24.1%

Andover (T) 788 0 0.0%

Andover (V) 1,042 0 0.0%

Angelica (T) 534 34 6.4%

Angelica (V) 869 199 22.9%

Belfast (T) 1,663 697 41.9%

Belmont (V) 969 31 3.2%

Birdsall (T) 221 1 <1%

Bolivar (T) 998 150 15.0%

Bolivar (V) 1,047 769 73.4%

Burns (T) 630 133 21.1%

Canaserga (V) 550 550 100.0%



Municipality Total Population

(2010 U.S. Census)

Population NEHRP Class "D" and "E" Soils

Total Population Exposed

Percent of Population Exposed

Caneadea (T) 2,542 1,511 59.4%

Centerville (T) 822 104 12.7%

Clarksville (T) 1,161 98 8.4%

Cuba (T) 1,669 156 9.3%

Cuba (V) 1,575 61 3.9%

Friendship (T) 2,004 166 8.3%

Genesee (T) 1,693 546 32.3%

Granger (T) 538 60 11.2%

Grove (T) 548 37 6.8%

Hume (T) 2,071 1,411 68.1%

Independence (T) 1,167 332 28.4%

New Hudson (T) 781 113 14.5%

Richburg (V) 450 276 61.3%

Rushford (T) 1,150 411 35.7%

Scio (T) 1,833 112 6.1%

Ward (T) 368 0 0.0%

Wellsville (T) 2,718 800 29.4%

Wellsville (V) 4,679 897 19.2%

West Almond (T) 334 0 0.0%

Willing (T) 1,228 328 26.7%

Wirt (T) 805 0 0.0%

Allegany County (Total) 48,946 10,376 21.2%

Sources: NYS DHSES 2008, U.S. Census 2010.

Note: NEHRP National Earthquake Hazard Reduction Program

Residents may be displaced or require temporary to long-term sheltering as a result of an earthquake

event. The number of people requiring shelter is generally less than the number displaced, as some

displaced persons use hotels or stay with family or friends following a disaster event. Table 5.4.3-8

estimates the number of households displaced, and population that may require short-term sheltering as a

result of the 100-, 500-, and 2,500-year MRP earthquake events.

Table 5.4.3-8. Summary of Estimated Sheltering Needs for Allegany County

Scenario Displaced

Households Persons Seeking

Short-Term Shelter

100-Year Earthquake 0 0

500-Year Earthquake 1 0

2,500-Year Earthquake 12 8




According to the 1999-2003 NYCEM Summary Report (Earthquake Risks and Mitigation in the New

York / New Jersey / Connecticut Region), a strong correlation exists between structural building damage

and number of injuries and casualties from an earthquake event. Further, time of day also exposes

different sectors of the community to the hazard. For example, HAZUS considers residential occupancy at

its maximum at 2:00 a.m., whereas educational, commercial, and industrial sectors are at their maximum

at 2:00 p.m., and peak commute time is at 5:00 p.m. Whether directly impacted or indirectly impacted, the

entire population will be affected to some degree. Business interruption could prevent people from

working, road closures could isolate populations, and loss of utilities could impact populations that

suffered no direct damage from an event.

HAZUS-MH estimated no injuries or casualties as a result of the 100-year event. Table 5.4.3-9 and Table

5.4.3-10 summarize county-wide injuries and casualties estimated for the 500- and 2,500-year MRP

earthquake events, respectively.

Table 5.4.3-9. Estimated Number of Injuries and Casualties from the 500-Year MRP Earthquake Event

Level of Severity Time of Day

2:00 AM 2:00 PM 5:00 PM

Injuries 1 1 1

Hospitalization 0 0 0

Casualties 0 0 0


Table 5.4.3-10. Estimated Number of Injuries and Casualties from the 2,500-Year MRP Earthquake Event

Level of Severity Time of Day

2:00 AM 2:00 PM 5:00 PM

Injuries 5 6 5

Hospitalization 1 1 1

Casaualities 0 0 0


Impact on General Building Stock

After consideration of populations, values of general building stock exposed to and damaged by 100-,

500-, and 2,500-year MRP earthquake events were evaluated. In addition, annualized losses were

calculated via application of HAZUS-MH. The entire County’s general building stock is considered at

risk and exposed to this hazard. Refer to the County Profile (Section 4) for county-wide general building

stock data replacement value statistics (structure and contents).

As stated earlier, soft soils (NEHRP Soil Classes D and E) can amplify ground shaking to damaging

levels even during a moderate earthquake (NYCEM 2003). Therefore, buildings located on NEHRP Class

D and E soils are at increased risk of damages from an earthquake. Table 5.4.3-11 below lists numbers and

replacement cost values (RCV) of buildings in Allegany County located on NEHRP D and E soils.



Table 5.4.3-11. Numbers and Replacement Cost Values of Buildings Located on NEHRP ‘D’ and ‘E’ Soils

Municipality

Total Number of Buildings

Total RCV (Structure and

Contents)

Buildings NEHRP Class "D" and "E" Soils

Number Exposed

Percent of Total Number RCV Exposed

Percent of Total RCV

Alfred (T) 588 $371,214,531 0 0.0% $0 0.0%

Alfred (V) 546 $550,636,847 0 0.0% $0 0.0%

Allen (T) 399 $162,300,474 36 9.0% $12,661,791 7.8%

Alma (T) 602 $256,374,017 2 <1% $404,717 <1%

Almond (T) 634 $312,231,916 48 7.6% $25,238,656 8.1%

Almond (V) 189 $135,692,850 0 0.0% $0 0.0%

Amity (T) 676 $334,307,982 163 24.1% $90,858,813 27.2%

Andover (T) 445 $230,686,817 8 1.8% $3,276,082 1.4%

Andover (V) 485 $338,015,430 0 0.0% $0 0.0%

Angelica (T) 391 $194,212,919 39 10.0% $21,664,946 11.2%

Angelica (V) 402 $284,974,634 107 26.6% $55,178,168 19.4%

Belfast (T) 961 $531,601,630 337 35.1% $215,666,440 40.6%

Belmont (V) 473 $396,945,690 20 4.2% $13,322,941 3.4%

Birdsall (T) 310 $115,899,500 16 5.2% $5,163,840 4.5%

Bolivar (T) 596 $258,709,425 111 18.6% $49,163,925 19.0%

Bolivar (V) 572 $409,452,702 469 82.0% $339,740,102 83.0%

Burns (T) 352 $176,932,773 126 35.8% $68,279,823 38.6%

Canaseraga (V) 280 $200,008,440 274 97.9% $196,843,678 98.4%

Caneadea (T) 1,010 $506,452,673 287 28.4% $155,540,638 30.7%

Centerville (T) 436 $220,631,685 55 12.6% $26,239,729 11.9%

Clarksville (T) 853 $289,246,885 39 4.6% $17,984,774 6.2%

Cuba (T) 971 $465,992,122 132 13.6% $63,840,522 13.7%

Cuba (V) 733 $602,554,836 45 6.1% $37,024,360 6.1%

Friendship (T) 1,067 $649,189,751 119 11.2% $71,540,042 11.0%

Genesee (T) 857 $366,042,711 336 39.2% $157,076,299 42.9%

Granger (T) 431 $182,924,910 23 5.3% $12,557,174 6.9%

Grove (T) 513 $203,653,283 77 15.0% $40,572,878 19.9%

Hume (T) 928 $595,483,501 563 60.7% $359,517,859 60.4%

Indpendence (T) 554 $317,936,823 204 36.8% $131,230,045 41.3%

New Hudson (T) 517 $250,742,307 69 13.3% $36,583,567 14.6%

Richburg (V) 199 $115,588,317 109 54.8% $57,401,926 49.7%

Rushford (T) 1,429 $676,861,880 248 17.4% $192,757,076 28.5%

Scio (T) 907 $431,175,535 69 7.6% $38,825,882 9.0%

Ward (T) 286 $115,902,946 0 0.0% $0 0.0%

Wellsville (T) 1,344 $720,536,730 452 33.6% $281,599,925 39.1%



Table 5.4.3-11. Numbers and Replacement Cost Values of Buildings Located on NEHRP ‘D’ and ‘E’ Soils

Municipality

Total Number of Buildings

Total RCV (Structure and

Contents)

Buildings NEHRP Class "D" and "E" Soils

Number Exposed

Percent of Total Number RCV Exposed

Percent of Total RCV

Wellsville (V) 2,565 $1,930,580,062 394 15.4% $240,122,066 12.4%

West Almond (T) 324 $146,702,356 7 2.2% $5,065,204 3.5%

Willing (T) 708 $322,582,548 305 43.1% $137,820,029 42.7%

Wirt (T) 598 $219,156,819 0 0.0% $0 0.0%

Allegany County

(Total) 26,131 14,590,137,257 5,289 20.2% $3,160,763,913 21.7%

Sources: NYS DHSES 2008, U.S. Census 2010

Notes:

DHSES Division of Homeland Security and Emergency Services

NEHRP National Earthquake Hazard Reduction Program NYS New York State

RCV Replacement cost value (estimated for both structure and contents)

For this HMP Update, a HAZUS-MH probabilistic model was run to estimate annualized dollar losses in

Allegany County. Annualized losses are useful for mitigation planning because they provide a baseline

from which to (1) compare risks from one hazard across multiple jurisdictions, and (2) compare degrees

of risk from all hazards in each participating jurisdiction. Annualized loss does not, however, predict what

losses will occur in any particular year. Estimated annualized losses in the County are approximately

$31 thousand per year (building and contents).

According to NYCEM, where earthquake risks and mitigation were evaluated in the New York, New

Jersey, and Connecticut region, most damage and loss caused by an earthquake results directly or

indirectly from ground shaking (NYCEM 2003). NYCEM found a strong correlation between PGA and

damage a building might undergo. The HAZUS-MH model is based on best available earthquake science

and aligns with these statements. HAZUS-MH methodology and model were applied to analyze effects

from the earthquake hazard on general building stock in Allegany County. See Figure 5.4.3-4 through

Figure 5.4.3-6 illustrating geographic distributions of PGA (%g) across the County during 100-, 500- and

2,500-year MRP events at the census-tract level.

In addition, according to NYCEM, a building’s construction determines how well it can withstand the

force of an earthquake. The NYCEM report indicates that unreinforced masonry buildings are most at risk

during an earthquake because the walls are prone to collapse outward, whereas steel and wood buildings

absorb more of the earthquake’s energy. Additional attributes that affect a building’s capability to

withstand an earthquake’s force include its age, number of stories, and quality of construction. HAZUS-

MH considers building construction and age of building as part of the analysis. Because the default

general building stock was used for this HAZUS-MH analysis, the default building ages and building

types already incorporated into the inventory were used.

Potential building damage was evaluated via application of HAZUS-MH across damage categories of

none, slight, moderate, extensive, and complete. Table 5.4.3-12 lists definitions of these five categories of

damage to a light wood-framed building; definitions of categories of damage to other building types

appear in HAZUS-MH technical manual documentation.



Table 5.4.3-12. Example of Structural Damage State Definitions for a Light Wood-Framed Building

Damage Category Description

None No damage recorded.

Slight Small plaster or gypsum-board cracks at corners of door and window openings and wall-ceiling

intersections; small cracks in masonry chimneys and masonry veneer.

Moderate

Large plaster or gypsum-board cracks at corners of door and window openings; small diagonal cracks

across shear wall panels exhibited by small cracks in stucco and gypsum wall panels; large cracks in brick

chimneys; toppled tall masonry chimneys.

Extensive

Large diagonal cracks across shear wall panels or large cracks at plywood joints; permanent lateral

movement of floors and roof; most brick chimneys toppled; cracks in foundations; splitting of wood sill

plates and/or slippage of structure over foundations; partial collapse of room-over-garage or other soft-story

configurations.

Complete

Large permanent lateral displacement of structure, possible collapse of structure, or possible imminent

danger of collapse due to cripple wall failure or failure of the lateral load resisting system; possible slippage

and fall of structure off foundation; large foundation cracks.

Source: HAZUS-MH Technical Manual.

Table 5.4.3-13 below lists estimated numbers of buildings damaged (within general occupancy

categories) during 500- and 2,500-year MRP earthquake events. Damage loss estimates include structural

and non-structural damage to the building and loss of contents. Table 5.4.3-14 below lists estimated RCVs

of buildings and contents damaged by 500- and 2,500-year MRP earthquake events. As noted earlier,

HAZUS-MH reports damages by U.S. census-tract. Table 5.4.3-15 below lists values of residential and

commercial buildings and contents in Allegany County damaged by the 500- and 2,500-year MRP

earthquake events (total RCVs are same as in Table 5.4.3-14). There are multiple municipalities located in

a census-tract; therefore municipal damages are grouped together in Table 5.4.3-14 and Table 5.4.3-15.

Table 5.4.3-13. Estimated Number of Buildings Damaged by General Occupancy during 500-year and 2,500-year MRP Earthquake Events

Category

Average Damage State

500-Year Mean Return Period (MRP) 2,500-Year MRP

None Slight Moderate Extensive Complete None Slight Moderate Extensive Complete

Residential 23,461

(89.8%)

196

(<1%)

50

(<1%)

3

(<1%)

0

(0%)

22,166

(84.8%)

1,141

(4.4%)

362

(1.4%)

38

(<1%)

3

(<1%)

Commercial 1,301

(5.0%)

17

(<1%)

4

(<1%)

0

(0%)

0

(0%)

1,203

(4.6%)

83

(<1%)

32

(<1%)

5

(<1%)

0

(0%)

Industrial 211

(<1%)

2

(<1%)

1

(<1%)

0

(0%)

0

(0%)

196

(<1%)

12

(<1%)

5

(<1%)

1

(<1%)

0

(0%)

Education,

Government,

Religious and

Agricultural

871

(3.3%)

10

(<1%)

2

(<1%)

0

(0%)

0

(0%)

806

(<1%)

54

(<1%)

21

(<1%)

2

(<1%)

0

(0%)

Source: HAZUS-MH 3.0



Table 5.4.3-14. Estimated Replacement Cost Values of Building and Contents Damaged by 500- and 2,500-Year MRP Earthquake Events

Municipality

Total Replacement Cost Value (RCV)

(Building and Contents)

Estimated Total Damages* Percent of Total Building

and Contents *

Annualized Loss 500-Year 2,500-Year


Alfred Town-Alfred Village-

Almond Town-Almond Village-

Amity Town-Ward Town-West

Almond Town

$1,265,880,325 $2,766 $219,069 $3,026,139 <1% <1% <1%

Alfred Town-Andover Town-

Andover Village-Independence

Town-Wellsville Town-Wellsville

Village

$1,115,187,715 $2,083 $178,536 $2,241,328 <1% <1% <1%

Allen Town-Amity Town-Angelica

Town-Angelica Village-Belfast

Town-Birdsall Town-Caneadea

Town-Friendship Town-Grove

Town-Hume Town-West Almond

Town

$1,237,777,702 $3,294 $237,372 $3,668,790 <1% <1% <1%

Alma Town-Bolivar Town-Scio


Village

$1,063,152,396 $1,873 $159,104 $2,022,570 <1% <1% <1%

Alma Town-Independence Town-

Wellsville Town-Wellsville

Village-Willing Town

$1,000,465,003 $1,712 $150,787 $1,826,732 <1% <1% <1%

Almond Town-Birdsall Town-

Burns Town-Canaserga Village-

Grove Town-West Almond Town

$861,137,111 $2,205 $164,317 $2,445,123 <1% <1% <1%

Amity Town-Andover Town-Scio

Town-Ward Town-Wellsville

Town-Wellsville Village

$1,582,559,028 $3,340 $269,489 $3,643,065 <1% <1% <1%

Amity Town-Angelica Town-

Angelica Village-Belmont Village-

Friendship Town-Scio Town

$1,248,714,970 $2,573 $207,071 $2,800,317 <1% <1% <1%

Belfast Town-Caneadea Town-

Cuba Town-Cuba Village-

Friendship Town-New Hudson

Town-Rushford Town

$1,525,362,795 $3,521 $261,952 $3,904,204 <1% <1% <1%

Bolivar Town-Bolivar Village-

Clarksville Town-Genesee Town-

Richburg Village-Wirt Town

$1,353,012,753 $2,253 $197,067 $2,398,244 <1% <1% <1%



Table 5.4.3-14. Estimated Replacement Cost Values of Building and Contents Damaged by 500- and 2,500-Year MRP Earthquake Events

Municipality



Estimated Total Damages* Percent of Total Building

and Contents *



Caneadea Town-Centerville Town-

Hume Town-Rushford Town $1,125,509,063 $3,133 $213,862 $3,578,434 <1% <1% <1%

Clarksville Town-Cuba Town-Cuba

Village-Friendship Town-Wirt

Town

$1,210,717,806 $2,408 $191,256 $2,648,126 <1% <1% <1%

Cuba Town $660,589 <$100 <$100 $1,374 <1% <1% <1%

Allegany County (Total) $14,590,137,257 $31,163 $2,449,975 $34,204,445 <1% <1% <1%


* Total Damages is sum of damages for all occupancy classes (residential, commercial, industrial, agricultural, educational, religious, and government).



Table 5.4.3-15. Estimated Values of Residential and Commercial Buildings and Contents Damaged by the 500- and 2,500-Year MRP Earthquake Events

Municipality



Estimated Residential Damage

Estimated Commercial Damage

500-Year 2,500-Year 500-Year 2,500-Year

Alfred Town-Alfred Village-

Almond Town-Almond Village-

Amity Town-Ward Town-West

Almond Town

$1,265,880,325 $168,714 $2,297,970 $33,766 $477,421

Alfred Town-Andover Town-

Andover Village-Independence


Village

$1,115,187,715 $144,872 $1,789,906 $15,294 $198,896

Allen Town-Amity Town-

Angelica Town-Angelica Village-

Belfast Town-Birdsall Town-

Caneadea Town-Friendship Town-

Grove Town-Hume Town-West

Almond Town

$1,237,777,702 $200,921 $3,049,756 $18,394 $311,469

Alma Town-Bolivar Town-Scio


Village

$1,063,152,396 $139,376 $1,754,523 $12,255 $160,127

Alma Town-Independence Town-

Wellsville Town-Wellsville

Village-Willing Town

$1,000,465,003 $128,471 $1,540,995 $10,778 $134,976

Almond Town-Birdsall Town-

Burns Town-Canaserga Village-

Grove Town-West Almond Town

$861,137,111 $133,323 $1,940,803 $12,579 $205,898

Amity Town-Andover Town-Scio

Town-Ward Town-Wellsville

Town-Wellsville Village

$1,582,559,028 $187,463 $2,502,474 $68,593 $944,200

Amity Town-Angelica Town-

Angelica Village-Belmont

Village-Friendship Town-Scio

Town

$1,248,714,970 $151,228 $1,982,128 $29,660 $418,167

Belfast Town-Caneadea Town-

Cuba Town-Cuba Village-

Friendship Town-New Hudson

Town-Rushford Town

$1,525,362,795 $221,919 $3,237,102 $22,525 $386,256

Bolivar Town-Bolivar Village- $1,353,012,753 $170,309 $2,045,517 $15,876 $205,971



Table 5.4.3-15. Estimated Values of Residential and Commercial Buildings and Contents Damaged by the 500- and 2,500-Year MRP Earthquake Events

Municipality



Estimated Residential Damage

Estimated Commercial Damage

500-Year 2,500-Year 500-Year 2,500-Year

Clarksville Town-Genesee Town-

Richburg Village-Wirt Town

Caneadea Town-Centerville

Town-Hume Town-Rushford

Town

$1,125,509,063 $158,275 $2,590,341 $19,299 $337,367

Clarksville Town-Cuba Town-

Cuba Village-Friendship Town-

Wirt Town

$1,210,717,806 $143,583 $1,947,708 $33,537 $479,296

Cuba Town $660,589 <$100 $1,374 $0 $0

Allegany County (Total) $14,590,137,257 $1,948,547 $26,680,596 $292,556 $4,260,043




HAZUS-MH 3.0 estimated approximately $2.4 million in building damages as a result of a 500-year

earthquake event. This includes structural damage, non-structural damage, and loss of contents

representing less than one (1) percent of total RCV of general building stock in Allegany County. From a

2,500-year MRP earthquake event, HAZUS-MH estimates greater than $34.2 million in building

damages—less than one (1) percent of total general building stock RCV. Residential and commercial

buildings account for greatest damage as a result of these earthquake events.

Earthquakes can cause secondary hazard events such as fires. HAZUS-MH estimates no fires as a result

of the 100-, 500- or 2,500-year MRP event.

Impacts on Critical Facilities

After consideration of general building stock exposed to and damaged by 100-, 500- and 2,500-year MRP

earthquake events, an evaluation of critical facilities occurred. All critical facilities (essential facilities,

transportation systems, lifeline utility systems, high-potential loss facilities, and user-defined facilities) in

Allegany County are considered exposed and vulnerable to the earthquake hazard. Refer to subsection

“Critical Facilities” in Section 4 (County Profile) of this HMP for a complete inventory of critical

facilities in Allegany County. Table 5.4.3-16 lists numbers of critical facilities by type located on NEHRP

soil class D or E. Because of their locations, these critical facilities have increased risk of damages from

an earthquake.

Table 5.4.3-16. Numbers of Critical Facilities Located on Soils of NEHRP Class D or E

Municipality

Facility Types

Co

mm

un

ica

tio

n

Em

erg

en

cy O

pe

rati

on

C

en

ter

Fir

e S

tati

on

His

tori

c R

eg

iste

r

Lib

rary

Me

dic

al

Nu

rsin

g C

are

Po

lice

Sta

tio

n

Sch

oo

l

Su

bst

ati

on

Alfred (T) 0 0 0 0 0 0 0 0 0 0

Alfred (V) 0 0 0 0 0 0 0 0 0 0

Allen (T) 0 0 0 0 0 0 0 0 0 0

Alma (T) 0 0 0 0 0 0 0 0 0 0

Almond (T) 0 0 0 0 0 0 0 0 0 0

Almond (V) 0 0 0 0 0 0 0 0 0 0

Amity (T) 1 0 0 1 0 0 0 1 0 0

Andover (T) 0 0 0 0 0 0 0 0 0 0

Andover (V) 0 0 0 0 0 0 0 0 0 0

Angelica (T) 0 1 0 1 0 0 0 0 0 0

Angelica (V) 0 0 0 1 0 0 0 0 0 0

Belfast (T) 0 0 0 0 1 0 0 0 1 0

Belmont (V) 0 0 1 1 1 1 0 1 1 0

Birdsall (T) 0 0 0 0 0 0 0 0 0 0

Bolivar (T) 0 0 0 0 0 0 0 0 0 0



Table 5.4.3-16. Numbers of Critical Facilities Located on Soils of NEHRP Class D or E

Municipality

Facility Types

Co

mm

un

ica

tio

n

Em

erg

en

cy O

pe

rati

on

C

en

ter

Fir

e S

tati

on

His

tori

c R

eg

iste

r

Lib

rary

Me

dic

al

Nu

rsin

g C

are

Po

lice

Sta

tio

n

Sch

oo

l

Su

bst

ati

on

Bolivar (V) 0 0 0 0 0 0 0 0 0 0

Burns (T) 0 0 0 0 0 0 0 0 0 0

Canaseraga (V) 0 0 1 1 1 0 0 0 1 1

Caneadea (T) 0 0 1 1 1 0 1 0 1 0

Centerville (T) 0 0 0 0 0 0 0 0 0 0

Clarksville (T) 0 0 0 0 0 0 0 0 0 0

Cuba (T) 0 0 0 0 0 0 0 0 0 0

Cuba (V) 0 0 0 0 0 3 1 0 0 0

Friendship (T) 0 0 0 0 0 0 0 0 0 0

Genesee (T) 0 0 0 1 1 0 0 0 0 0

Granger (T) 0 0 0 0 0 0 0 0 0 0

Grove (T) 0 0 0 0 0 0 0 0 0 0

Hume (T) 0 0 2 0 1 1 0 1 1 0

Indpendence (T) 0 0 1 0 1 0 0 1 0 0

New Hudson (T) 0 0 0 0 0 0 0 0 0 0

Richburg (V) 0 0 0 0 0 0 0 0 0 1

Rushford (T) 0 0 1 0 1 0 0 0 0 0

Scio (T) 0 0 0 0 0 0 0 0 0 0

Ward (T) 0 0 0 0 0 0 0 0 0 0

Wellsville (T) 0 0 0 0 0 0 0 0 0 0

Wellsville (V) 0 0 0 0 0 1 0 0 2 0

West Almond (T) 0 0 0 0 0 0 0 0 0 0

Willing (T) 0 0 1 0 0 0 0 0 0 0

Wirt (T) 0 0 0 0 0 0 0 0 0 0

Allegany County (Total) 1 1 8 7 8 6 2 4 7 2

Source: NYS DHSES 2008, Allegany County 2016

HAZUS-MH 3.0 estimates probabilities that critical facilities may sustain damage as a result of 100-,

500-, and 2,500-year MRP earthquake events. Additionally, HAZUS-MH estimates percent functionality

of each facility days after the event. During and following 100- and 500-year MRP events, HAZUS-MH

3.0 estimates that emergency facilities (police, fire, Emergency Medical Services [EMS] and medical

facilities), schools, utilities, and specific facilities identified by Allegany County as critical would be

nearly 100 percent functional. Effects on critical facilities from the 100- and 500-year events would not

be significant. Not so from the 2,500-year MRP earthquake event: Table 5.4.3-17 lists percent



probabilities of critical facilities sustaining damages in various categories, and lists percent functionalities

of critical facilities after various time spans following the 2,500-year MRP earthquake event.

Table 5.4.3-17. Estimated Damage and Loss of Functionality for Critical Facilities and Utilities for the 2,500-Year MRP Earthquake Event

Name

Percent Probability of Sustaining Damage Percent Functionality

None Slight Moderate Extensive Complete Day 1 Day 7 Day 30 Day 90

Critical Facilities

Medical 84-88 8-10 3-5 <1 <! 84-88 94-96 99 100

Police 76-88 8-14 3-8 0.5-2 <1 76-88 90-96 98-99 99-100

Fire 84-89 8-10 3-5 <1 <1 84-88 94-96 99 100

EOC 86.5 9 3.8 <1 <1 86 95 99 100

School 77-88 8-14 3-8 0.5-2 <1 77-88 90-96 98-99 99-100

Utilities

Electric Facility 91-94 5-7 2-3 <1 0 94-96 100 100 100

Communication 0 0 0 0 1 16 20 40 89


Impact on Economy

Earthquakes also impact the economy, including loss of business function, damage to inventory,

relocation costs, wage loss, and rental loss due to repair and replacement of buildings. A Level 2 HAZUS-

MH analysis estimated total economic loss associated with each earthquake scenario, including building-

and lifeline-related losses (transportation and utility) based on available inventory (facility or Geographic

Information System [GIS] point data only). Direct building losses are estimated costs to repair or replace

damage to buildings. This is reported in the “Impact on General Building Stock” section discussed earlier.

Lifeline-related losses include direct costs to repair transportation and utility systems, and are reported in

terms of probability of reaching or exceeding a specified level of damage when these systems are

subjected to a given level of ground motion. Additionally, economic loss includes business interruption

losses associated with inability to operate a business due to damage sustained during the earthquake, as

well as temporary living expenses for those displaced. These losses are discussed below.

From the 100-year event, HAZUS-MH 3.0 estimates $0 in income loss (wage, rental, relocation, and

capital-related losses) and capital stock losses (structural, non-structural, content, and inventory losses).

From the 500-year event, HAZUS-MH 3.0 estimates the County would incur nearly $500,000 in income

losses (wage, rental, relocation, and capital-related losses) and $2.5 million in structural, non-structural,

content, and inventory losses.

From the 2,500-year event, HAZUS-MH 3.0 estimates the County would incur approximately

$4.3 million in income losses, mainly to residential and commercial occupancy classes associated with

wage, rental, relocation, and capital-related losses; an additional estimated $34.2 million in structural,

non-structural, content, and inventory losses is anticipated.

Although the HAZUS-MH analysis did not compute estimates of damages to roadway segments and

railroad tracks, assumedly these features would undergo damages due to ground failure—resulting in

interruptions of regional transportation and of distribution of materials. Losses to the community that

would result from damage to lifelines could much exceed costs of repair (FEMA 2012).



Earthquake events can significantly affect road bridges, many of which provide the only access to certain

neighborhoods. Because softer soils generally follow floodplain boundaries, bridges that cross

watercourses should be considered vulnerable. Another key factor in degree of vulnerability is age of

facilities and infrastructure, which correlates with standards in place at times of construction of these.

HAZUS-MH estimated economic impacts on the County for 15 years after an earthquake event—in the

category of transportation infrastructure, $1.5 million for repair of highway bridges as a result of a

2,500-year event, less than $500,000 for that purpose as a result of a 500-year event, and no costs

estimated for that as a result of a 100-year event.

HAZUS-MH 3.0 also estimated volume of debris that may be generated as a result of an earthquake event

to enable the study region to prepare for and rapidly and efficiently manage debris removal and disposal.

Debris estimates were divided into two categories: (1) reinforced concrete and steel that require special

equipment to break up before transport of these can occur, and (2) brick, wood, and other debris that can

be loaded directly onto trucks by use of bulldozers (HAZUS-MH Earthquake User’s Manual).

HAZUS-MH 3.0 estimated that no debris would result from the 100-year event. HAZUS-MH 3.0

estimated generation of more than 1,000 tons of debris during the 500-year MRP event, and more than

8,000 tons of debris during the 2,500-year MRP event. Table 5.4.3-18 below lists estimated debris

amounts by U.S. Census tract during 500- and 2,500-year events.

Table 5.4.3-18. Estimated Debris Generated by the 500- and 2,500-year MRP Earthquake Events

Municipality

500-Year 2,500-Year

Brick/Wood (tons)

Concrete/Steel (tons)

Brick/Wood (tons)


Alfred Town-Alfred Village-Almond Town-

Almond Village-Amity Town-Ward Town-West

Almond Town

88.3 20.0 541.8 187.1

Alfred Town-Andover Town-Andover Village-

Independence Town-Wellsville Town-Wellsville

Village

74.2 15.9 441.2 137.5

Allen Town-Amity Town-Angelica Town-

Angelica Village-Belfast Town-Birdsall Town-

Caneadea Town-Friendship Town-Grove Town-

Hume Town-West Almond Town

90.0 21.2 609.6 216.6

Alma Town-Bolivar Town-Scio Town-Wellsville

Town-Wellsville Village 68.3 14.5 411.1 125.5

Alma Town-Independence Town-Wellsville

Town-Wellsville Village-Willing Town 64.3 14.2 376.8 118.5

Almond Town-Birdsall Town-Burns Town-

Canaserga Village-Grove Town-West Almond

Town

63.8 14.7 416.2 144.8

Amity Town-Andover Town-Scio Town-Ward

Town-Wellsville Town-Wellsville Village 108.8 26.0 660.5 237.6

Amity Town-Angelica Town-Angelica Village-

Belmont Village-Friendship Town-Scio Town 78.7 18.3 487.9 167.1

Belfast Town-Caneadea Town-Cuba Town-Cuba

Village-Friendship Town-New Hudson Town-

Rushford Town

103.9 25.6 684.6 251.3

Bolivar Town-Bolivar Village-Clarksville Town-

Genesee Town-Richburg Village-Wirt Town 85.4 18.1 516.0 153.3

Caneadea Town-Centerville Town-Hume Town-

Rushford Town 80.4 18.5 557.2 197.9

Clarksville Town-Cuba Town-Cuba Village-

Friendship Town-Wirt Town 77.6 17.8 488.6 164.0



Municipality

500-Year 2,500-Year

Brick/Wood (tons)


Brick/Wood (tons)


Cuba Town 0.0 0.0 0.2 0.1

Allegany County (Total) 983.8 224.7 6,191.7 2,101.4

Source: HAZUS-MH 3.0

Future Growth and Development

As discussed in Section 4, areas targeted for future growth and development have been identified across

the County. Human exposure and vulnerability to earthquake impacts in newly developed areas are

expected to be similar to those current within the County. Current building codes require seismic

provisions that should render new construction less vulnerable to seismic impacts than older, existing

construction which may have been built when lower construction standards were in place.

New development within areas with softer NEHRP soil classes may also be more vulnerable to the

earthquake hazard. Potential new development on NEHRP Soil Classes B, C, and E has been identified.

Change of Vulnerability

The 2011 HMP summarized past events and indicated Allegany County’s earthquake vulnerability in

relation to locations of faults in the State. A HAZUS-MH analysis did not occur as part of the 2011 HMP.

This HMP update incorporated updated population data and an updated general building stock into the

HAZUS-MH model, and a probabilistic assessment occurred. The County continues to be vulnerable to

earthquake events.

Additional Data and Next Steps

Allegany County can identify unreinforced masonry in critical facilities and privately-owned buildings

(i.e., residences) by accessing local knowledge and/or pictometry/orthophotos. These buildings may not

withstand earthquakes of certain magnitudes, and plans to provide emergency response/recovery efforts at

these properties can be developed. Further mitigation actions can include training county and municipal

personnel to provide post-hazard event rapid visual damage assessments, increasing county and local

debris management and logistic capabilities, and revising regulations to prevent additional construction of

buildings with non-reinforced masonry.

Section 5.4.3: Earthquake...Richter Magnitude Earthquake Effects 2.5 or less Usually not felt, but...

Documents

Transcript of Section 5.4.3: Earthquake...Richter Magnitude Earthquake Effects 2.5 or less Usually not felt, but...