U.S. Department of the Interior

U.S. Geological Survey

Scientific Investigations Report 2007–5255

Converting NAD83 GPS Heights Into NAVD88 Elevations with 

LVGEOID, a Hybrid Geoid Height Model for the Long Valley 

Volcanic Region, California
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Converting NAD83 GPS Heights Into 

NAVD88 Elevations With LVGEOID, a Hybrid 

Geoid Height Model for the Long Valley 

Volcanic Region, California

By Maurizio Battaglia, Daniel Dzurisin, John Langbein, Jerry Svarc, and 

David P. Hill

Scientific Investigations Report 2007–5255

U.S. Department of the Interior

U.S. Geological Survey
U.S. Department of the Interior

DIRK KEMPTHORNE, Secretary

U.S. Geological Survey

Mark D. Myers, Director

U.S. Geological Survey, Reston, Virginia: 2007

This report and any updates to it are available at:

http://pubs.usgs.gov/sir/2007/5255/ 

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U.S. Government.

Although this report is in the public domain, permission must be secured from the individual copyright owners to 

reproduce any copyrighted materials contained within this report.

Suggested citation:

Battaglia, M., Dzurisin, D., Langbein, J., Svarc, J. and Hill, D.P., 2007, Converting NAD83 GPS heights into NAVD88 

elevations with LVGEOID, a hybrid geoid height model for the Long Valley volcanic region, California: U.S. Geological 

Survey Scientific Investigation Report 2007-5255, 32 p. [http://pubs.usgs.gov/sir/2007/5255/].

Manuscript approved for publication, November 13, 2007

Text edited by James W. Hendley II

Layout by Luis Menoyo
iii

Contents

Abstract ..........................................................................................................................................................1

Introduction.....................................................................................................................................................1

Comparing GPS and Leveling ......................................................................................................................4

Leveling............................................................................................................................................................4

Helmert Orthometric Heights.......................................................................................................................5

GPS Ellipsoidal Heights.................................................................................................................................5

The Geoid Height Model...............................................................................................................................6

The Long Valley Caldera Hybrid Geoid Height Model LVGEOID ...........................................................6

Conversion Surface..............................................................................................................................6

Summary and Conclusions...........................................................................................................................8

Acknowledgments.......................................................................................................................................12

References Cited..........................................................................................................................................12

Appendix. Geostatistical Analysis.............................................................................................................13

Spatial Interpolation...........................................................................................................................13

Assessment of Spatial Uncertainty .................................................................................................14

Tables 1–5......................................................................................................................................................16

Figures

1. Map of Long Valley volcanic region with GPS on leveled Bench Mark (GPSBM)

sites and leveling routes..............................................................................................................2

2. Relationship between the ellipsoid height h, orthometric height H, and 

geoid height N...............................................................................................................................4

3. Profiles of the measured geoid and GEOID03 along the GPS-on-Bench Mark sites

in the Long Valley region .............................................................................................................7

4. Geoid height profiles from leveling surveys in the Long Valley region................................9

5. Map of the difference between LVGEOID and the GEOID03NGS geoid height model

in the Long Valley region ...........................................................................................................10

6. Vertical deformation in the Long Valley region measured along the two leveling

routes occupied in the summer of 2006 ..................................................................................11

7. Vertical deformation at the permanent GPS site RDOM in Long Valley Caldera .............12

8. Histogram of the conversion surface......................................................................................13

9. Conversion surface variogram inferred from the 25 measured values.............................14

10. Histograms of the conversion surface (normal score) and the simulations ....................15

11. Normal score variogram inferred from the 25 measured values .......................................15
iv

Tables

1. Leveling heights for the Long Valley region ...........................................................................17

3. Experimental hybrid geoid height (N+s) for the Long Valley region...................................23

4. Experimental conversion surface s for the Long Valley region ..........................................24

5. Geoid heights at leveling benchmarks for the Long Valley region.....................................25

6. Ninty-five-percent bounds on intrusion source parameters ................................................8

7. Cross-validation of the variogram model for the conversion surface...............................14

8. Cross-validation of the variogram model the normal score................................................15

2. Long Valley region GPS-on-Bench Mark survey for 2006................ ...................................22
Abstract 

A GPS survey of leveling benchmarks done in Long 

Valley Caldera in 1999 showed that the application of the 

National Geodetic Survey (NGS) geoid model GEOID99 to 

tie GPS heights to historical leveling measurements would 

significantly underestimate the caldera ground deformation (known from other geodetic measurements). The NGS 

geoid model was able to correctly reproduce the shape of the 

deformation, but required a local adjustment to give a realistic estimate of the magnitude of the uplift. In summer 2006, 

the U.S. Geological Survey conducted a new leveling survey 

along two major routes crossing the Long Valley region from 

north to south (Hwy 395) and from east to west (Hwy 203 – 

Benton Crossing). At the same time, 25 leveling bench marks 

were occupied with dual frequency GPS receivers to provide a 

measurement of the ellipsoid heights. Using the heights from 

these two surveys, we were able to compute a precise geoid 

height model (LVGEOID) for the Long Valley volcanic region. 

Our results show that although the LVGEOID and the latest 

NGS GEOID03 model practically coincide in areas outside 

the caldera, there is a difference of up to 0.2 m between the 

two models within the caldera. Accounting for this difference 

is critical when using the geoid height model to estimate the 

ground deformation due to magmatic or tectonic activity in the 

caldera.

Introduction

The Global Positioning System (GPS) is commonly 

referred to as a three-dimensional positioning system, but 

heights obtained from GPS are typically expressed as elevations above an ellipsoidal model of the Earth, and not the 

Earth’s actual surface. As a result, GPS ellipsoidal heights are 

not directly comparable with heights above mean sea level, 

known as orthometric heights, determined by leveling surveys. 

The conversion from ellipsoid to orthometric heights requires 

a geoid height model that relates the local ellipsoid to the local 

geoid, where the geoid is the “equipotential surface” which 

would coincide exactly with the mean ocean surface (sea 

level) of the Earth. The difference between these two surfaces 

can be as large as 100 m in areas with strong topographic or 

subsurface density gradients. 

A GPS survey of leveling benchmarks done in Long 

Valley in 1999 showed that straightforward application of 

the National Geodetic Survey (NGS) hybrid geoid model 

GEOID99 to tie GPS heights to historical leveling measurements significantly underestimated the caldera ground 

deformation as measured with other geodetic techniques (see 

Battaglia and others, 2003, for full discussion). The NGS 

geoid model was able to correctly reproduce the shape of the 

deformation, but needed a local adjustment to give a realistic 

estimate of the magnitude of the uplift.

In December 2003, the NGS released the new GEOID03 

geoid height model (http://www.ngs.noaa.gov/GEOID). 

The GEOID03 model was developed in the same manner as 

GEOID99 using an underlying gravimetric geoid, USGG2003, 

and updated GPS ellipsoidal heights on leveled Bench Marks 

(GPSBMs). The conversion surface for GEOID03 was developed from 14,185 GPSBMs at a 5 arc-minute grid interval, 

which provided a substantial increase in the spatial coverage 

over GEOID99 and reduced errors due to interpolation. The fit 

to these same points afterwards using the derived GEOID03 

model was within 0.0048 m (2σ) which is comprised of both 

correlated (attributable to GEOID03) and uncorrelated (GPS 

observation error) signals (Roman and others, 2004). 

In summer 2006, the USGS conducted a new leveling 

survey along two major routes crossing the Long Valley region 

from north to south (HWY 395) and from east to west (HWY 

203 – Benton Crossing). At the same time, 25 leveling bench 

marks were occupied with dual frequency GPS receivers 

to provide a measurement of the ellipsoid heights (fig. 1A). 

Using the heights from these two surveys we were able to (1) 

Converting NAD83 GPS Heights Into NAVD88 Elevations 

With LVGEOID, a Hybrid Geoid Height Model for the Long 

Valley Volcanic Region, California

By Maurizio Battaglia1, Daniel Dzurisin2, John Langbein3, Jerry Svarc3, and David P. Hill3

1

University of Rome “La Sapiensa”, Rome, Italy.

2

U.S. Geological Survey, Cascades Volcano Observatory, Vancouver, WA.

3

U.S. Geological Survey, Menlo Park, CA.
2 Converting NAD83 GPS Heights Into NAVD88 Elevations With LVGEOID, Long Valley Volcanic Region, California

C916

JUCTION

BM7

Mono

Lake

Glass Mt

Long Valley caldera

Mono Domes

Crowley

Lake

Lee Vining

Tom’s Place

Inyo Craters

Mammoth

Mt

395

CA

203

T2SR

X123

EAL15

D916

13DOR

RET

PM14 5JCM

K1383

2JCM

A124R CONVICT

V911

D124

CROWLEY

1EGE

18EGE

25EGE

KWH6

25JCM 26JCM

44DOR

29JCM

T3SR

4JD

RDOM

N

GPSBM 2006

GPSBM 03

Leveling route

0 5 10 15 KILOMETERS

EXPLANATION

A -119.0 -188.8 -118.6

37.6 37.8 38.0

Figure 1. (A) Map of Long Valley volcanic region with GPS on leveled Bench Mark (GPSBM) sites and leveling routes. The GPSBM 

03 label identifies the sites belonging to the NGS GEOID03 data base, whereas GPSBM 2006 the sites occupied by the U.S. Geological 

Survey in July 2006; (B) Map of Long Valley leveling routes and benchmarks.
Introduction 3

W123RST

B1391

15DOR

69.97RT

EAL12

CROWLEY

C1433 P911RST

Sherwin Creek Spur

Mary Lake Rd

Mono Lake

Crowley Lake

June 

Lake

Convict

Lake

Grant

Lake

Long Valley

caldera

-119.0 -188.8 

37.6 37.8

B

Leveling routes and benchmarks

Line 1: Hwy 395

Line 2: Hwy 203

Line 3: Big Loop

Line 4: Small Loop

Line 5: Small Loop

Line 6: Long Valley

Line 7: Convict Lake

Line 8: Deadman Spur

0 5 10 KILOMETERS

EXPLANATION

N

Figure 1. (A) Map of Long Valley volcanic region with GPS on leveled Bench Mark (GPSBM) sites and leveling 

routes. The GPSBM 03 label identifies the sites belonging to the NGS GEOID03 data base, whereas GPSBM 2006 the 

sites occupied by the U.S. Geological Survey in July 2006; (B) Map of Long Valley leveling routes and 

benchmarks—Continued.
4 Converting NAD83 GPS Heights Into NAVD88 Elevations With LVGEOID, Long Valley Volcanic Region, California

assess the accuracy of GEOID03 in the region, (2) improve the 

estimate of the local adjustment to the geoid height model, and 

(3) compute a precise geoid height model (LVGEOID) for the 

Long Valley volcanic region.

Our results show that while LVGEOID and GEOID03 

closely coincide in areas outside the caldera, the two models 

differ by as much as 0.2 m within the caldera. Accounting for 

this difference is critical when using a geoid height model to 

estimate ground deformation due to magmatic and tectonic 

unrest within the caldera.

Comparing GPS and Leveling

Before vertical GPS measurements can be compared 

with leveled heights to obtain vertical displacements, the 

heights must be transformed into the same reference frame 

(fig. 2). The reference surface for leveling is the geoid, an 

equipotential surface closely identified with mean sea level 

(Rapp, 1980). To obtain a homogeneous set of elevations 

from different leveling surveys, raw leveling heights must be 

referenced to a common vertical datum. The present vertical 

datum for the United States is the North American Vertical 

Datum of 1988 (NAVD88). NAVD88 elevations are expressed 

by Helmert orthometric heights, which can be computed 

using the Helmert orthometric reduction (Zilkoski and others, 1992). GPS solutions, however, produce a set of XYZ 

coordinates that are referenced to the center of an ellipsoid 

that approximates the Earth’s surface. To obtain heights from 

GPS solutions, the XYZ coordinates must be transformed 

into geodetic latitude, longitude, and ellipsoidal heights. This 

transformation is usually performed using the World Geodetic 

System WGS84 ellipsoid model (Snay and Soler, 2000). In the 

conterminous United States, horizontal coordinates in WGS84 

are practically identical to those of the present North American horizontal Datum of 1983 (NAD83); the two systems 

agree at the 0.1 mm level (Langley, 1992). Geoid and ellipsoid surfaces, however, do not coincide. The vertical distance 

between the ellipsoid and the geoid is called the geoid height 

or the ellipsoid-geoid separation, N. An elevation measured 

with respect to the geoid (for example, by leveling) is called an 

orthometric height, and an elevation determined with respect 

to the reference ellipsoid (for example, by GPS) is called an 

ellipsoidal height. The value of N ranges from -100 m in Sri 

Lanka to +70 m in the Marianas Trench. GPS heights can be 

transformed into the same reference frame as leveled heights 

by using an appropriate geoid height model (Smith and Milbert, 1999). Geoid height models developed by the National 

Geodetic Survey enable one to directly convert between 

NAD83 GPS heights and NAVD88 leveling heights within the 

United States (http://www.ngs.noaa.gov/GEOID/).

Leveling

Beginning in 1975, a series of repeated leveling surveys, 

in which orthometric height differences between stations 

are measured with a precise optical level, have been used to 

measure vertical deformation along the 65-km-long line along 

Hwy 365 from Tom’s Place to Lee Vining and along several 

other routes within Long Valley caldera (fig. 1B; tables 1–5 

are at the back of this report). Bench mark C916 (fig. 1) is the 

elevation datum for all the leveling surveys. In other words, 

the height of C916 is assumed to be fixed. This assumption 

introduces a small bias in heights determined by any given 

survey, but it does not affect the shape of the vertical displacement field computed by differencing two surveys. The 

magnitude of the bias is unknown, but the flat shape of vertical 

displacement profiles along Hwy 395 in the vicinity of C916 

suggests that any real motion there is small (that is, no more 

than a few millimeters). 

The Highway 395 route was surveyed in 1932, 1957, 

1975, 1980, each summer from 1982 to 1988, 1992, 1995, 

1997 and 2006. Complete leveling of the caldera occurred 

each summer from 1982 to 1986, and in 1988 and 1992 (Langbein and others, 1995). The leveling surveys were run to standards equal to those required for first-order, class II surveys, as 

established by the National Geodetic Survey (Federal Geodetic Control Committee, 1984). The standard error for height 

differences between marks determined by a single survey can 

be taken to be 0.7 mm·km1/2/L1/2, where L is the cumulative 

distance between bench marks in km (http://www.ngs.noaa.

gov/heightmod/Leveling/requirements.html). The standard 

(white noise) error for height changes computed by differencing results of two surveys is 1.0 mm·km1/2/L1/2. Leveling 

observations were corrected for rod scale and temperature, 

level collimation, and for astronomic, refraction and magnetic 

effects (Balazs and Young, 1982). In general, leveling surveys 

are not referenced to the NAVD88 datum because the U.S. 

Geological Survey (USGS) is mainly interested in monitoring relative elevation changes within the caldera, rather than 

determining absolute elevations. 

H 

MSL Geoid 

WGS84 (Ellipsoid) 

h 

N 

h: GPS ellipsoid heights 

H: Levelled orthometric height 

N: Geoid height 

H = h-N 

MSL = mean sea level 

Figure 2. Relationship between the ellipsoid height h, 

orthometric height H, and geoid height N.
GPS Ellipsoidal Heights 5

Helmert Orthometric Heights

The first stage in the computation of a geoid height model 

within Long Valley Caldera requires the 2006 leveling survey 

to be referenced to the NAVD88 vertical datum by transforming the raw leveling heights into Helmert orthometric heights 

(Milbert and Smith, 1996). The NAVD 88 datum is expressed 

in Helmert orthometric heights, and was computed in 1991. 

The NAVD 88 datum was realized by a single datum point, 

Father Point/Rimouski, in Quebec, Canada. The strategy and 

the value of the constraint were based on a number of factors. 

But, the foremost requirement was to minimize recompilation 

of national mapping products. 

The transformation is a two-step process – (1) the geopotential number associated with a leveling bench mark is 

computed, and (2), the Helmert height using the orthometric 

reduction formula (Heiskanen and Moritz, 1967, p. 167) is 

calculated. 

The geopotential number CB represents the difference 

between the potential at the geoid and the potential at the 

observation point B on the Earth’s surface (Heiskanen and 

Moritz, 1967, p. 162)

CB = W0 − WB = gdh

0

hB

∫ , (1)

where 0 is a point at mean sea level (on the geoid), hB is the 

raw leveling height at point B relative to 0, g is the external 

gravity (a function of the elevation h), and W is the gravitational potential. If A is the leveling survey datum (or primary 

base station) and B a second point on the leveling route, we 

have

CB = W0 − WB = (W0 − WA) + (WA −WB) = CA + gdh

hA

hB

∫ , (2)

For normal orthometric heights, CA is given by (Heiskanen and Moritz, 1967, p. 162)

CA = γ 0H dyn , (3)

where Hdyn is a local dynamic height expressed in the NAVD88 

vertical datum and γ 0 is, by convention, the normal gravity 

value computed on the Geodetic Reference System ellipsoid of 

1980 (GRS80) at 45° degrees latitude. Dynamic heights scale 

the geopotential number by a global constant γ 0

 = 980.6199 

gal, converting the geopotential number into a length. The 

dynamic height for the bench mark C916 (the elevation 

datum for the Long Valley Caldera leveling network) is Hdyn

= 2071.409 m (see the data sheet for C916, PID = HR0097, 

available from the NGS server at http://www.ngs.noaa.gov/cgibin/datasheet.prl). To solve the integral in equation , values of 

the surface gravity g at every leveling bench mark between A

and are necessary. These values may be computed using the 

NAVD 88 Modeled Gravity software, available from the NGS 

server at http://www.ngs.noaa.gov/TOOLS. Geopotential numbers are measured in g.p.u. (geopotential units), where 1 g.p.u. 

= 1 kgal m = 10 ms-2 m. 

To compute the orthometric height at B, CB is substituted 

into the Helmert’s height reduction formula (Heiskanen and 

Moritz, 1967, p. 167)

HB = CB

g = CBg + 0.0424HB

, (4)

where HB is the orthometric height expressed in 103 m and 

g is the mean value of the gravity along the plumb line 

between the geoid and the surface. Using the simplified Prey 

reduction formula for the gravity, then g = g + 0.0424HB

(Heiskanen and Moritz, 1967, p. 167), where g is the gravitational acceleration at B expressed in gal (1 gal = 0.01 m/s2

). 

The approximated formula (4) is often sufficient for standard 

topography. Solving the algebraic equation yields the value 

for the orthometric height at the leveling bench mark B

HB = −g + g

2

+4 ×0.0424CB

2 × 0.0424 , (5)

Orthometric heights for the 2006 leveling survey are 

shown in table 1. The difference between the lowest (U123) 

and the highest (RET) leveled elevations is about 750 m. The 

standard errors for orthometric heights, taken to be the same 

as those of the leveled elevations (Zilkoski and others, 1992), 

range from 1 mm (station U123) to 6 mm (station F124) and 

average 5 mm within the caldera.

GPS Ellipsoidal Heights

During the GPS survey in 2006, phase and pseudorange 

data were recorded on Ashtech Z-12 and Z-Xtreme receivers using Dorne-Margolin choke-ring antennas. Data were 

recorded for sessions that lasted at least 6 hours at every 

sites. GPS survey sites were chosen based on their relatively 

uniform spacing along the leveling lines and good sky view 

(to maximize the data quality). At some locations, 5JCM and 

18EG in particular, the sky view was not completely clear but 

was better than other nearby leveling sites. 

GPS data were processed with the Gipsy/Oasis II software (Lichten and Border, 1987), using a bias-fixed, fiducialfree, precise point positioning strategy (Zumberge and others,

1997). We did not solve for the satellite orbits or clock errors, 

using instead solutions for these parameters provided by 

the Jet Propulsion Laboratory (JPL). Further precision was 

obtained by regional filtering, which removes most of com-
6 Converting NAD83 GPS Heights Into NAVD88 Elevations With LVGEOID, Long Valley Volcanic Region, California

mon-mode signals (Wdowinski and others, 1997). An elevation mask of 15 degrees was used during data processing. 

We included a globally distributed subset of IGS stations, 

typically 25 to 30 stations, in our solutions. Using the ITRF00 

positions of these stations, a Helmert transformation was done 

to transform each daily solution into the ITRF00 reference 

frame. The ITRF00 XYZ solutions were transformed into 

geodetic latitude, longitude, and ellipsoidal heights using the 

NAD83 ellipsoidal model for the conterminous United States 

and the Horizontal Time Dependent Positioning (HTDP) software, available from the NGS server at http://www.ngs.noaa.

gov/TOOLS. GPS ellipsoid heights and their uncertainties 

for the 2006 survey are reported in table 2. The formal errors 

obtained in the GIPSY solutions have been scaled by a factor 

of two to produce a scaled formal error level that approximates 

the observed RMS about the linear fit to the time series. The 

errors also include both white noise and random walk components (Prescott and others, 2001). Uncertainties in the GPS 

ellipsoidal heights range from 12 mm (station D124) to 42 mm 

(station 5JCM), averaging 19 mm. 

The Geoid Height Model

Equation (6) gives the general relationship between 

ellipsoid heights (heights between the external surface and the 

ellipsoid), h, orthometric heights (heights between the external 

surface and the geoid), H, and geoid height (distance between 

the ellipsoid and the geoid), N (see fig. 2)

h = H + N, (6)

In the conterminous United States, the geoid surface is 

beneath the ellipsoid; thus, geoid heights N are negative, and 

the ellipsoidal height h is smaller in magnitude than the orthometric height H at a given point. By subtracting the orthometric heights H from the ellipsoid heights h, we obtain the geoid 

heights N (Milbert and Smith, 1996). 

Gravity points, digital elevations, and altimetrically 

derived gravity anomalies can be processed to compute a geocentric gravimetric geoid height model (Smith, 1998; Roman 

and others, 2004). We cannot, however, transform directly 

between NAD83 GPS ellipsoid heights and NAVD88 orthometric heights using a gravimetric geoid. There is a systematic 

offset between the NAVD 88 reference level and the current 

best estimate of global mean sea level, and a transcontinental 

tilt is introduced by the non-geocentricity of the NAD83 ellipsoid (Smith and Milbert, 1999), which prevents the conversion. To complete the transformation between GPS ellipsoid 

heights and orthometric heights, the gravimetric geoid height 

N, the ellipsoidal heights h and the orthometric heights H must 

be related through an empirical conversion surface s (Milbert, 

1995; Kotsakis and Sideris, 1999). If subscripts are used to 

denote the height reference systems, then we can rewrite as

H88 = h83 - (N+s), (7)

where H88 indicates the GPS-based orthometric heights relative to NAVD88 and h83 the GPS ellipsoid heights relative to 

NAD83. The new geoid model N+s is called a hybrid geoid 

(Smith and Milbert, 1999). The most recent gravimetric geoid 

model (USGG2003) and hybrid geoid model (GEOID03) for 

the conterminous United States were released by the National 

Geodetic Survey in December 2003 (Roman and others, 2004; 

http://www.ngs.noaa.gov/GEOID/). Using these models, the 

leveled orthometric heights H88 (table 1) can be subtracted 

from the GPS ellipsoid heights h83 (table 2) to compute the 

experimental value of the hybrid geoid model N+s at the 25 

colocated leveling and GPS benchmarks in Long Valley Caldera (table 3). 

The measured geoid height model can then be compared 

against the published NGS GEOID03 model (fig. 3). The profiles shown in fig. 3 indicate that the geoid shapes are similar, 

but the NGS model underestimates the geoid height within the 

caldera. In particular, the difference reaches a maximum at 

sites on the caldera’s resurgent dome and appears negligible at 

Lee Vining and Tom’s Place, outside the caldera to the north 

and south, respectively. The GEOID03 model is globally accurate but requires a local adjustment (Smith and Roman, 1999), 

probably because the NGS used only six GPS/leveling comparisons (BRIDGEPORT, E 818, JUCTION, OASIS, T 1391, 

X 123) to estimate the conversion surface s in Mono County 

(http://www.ngs.noaa.gov/GEOID/GPSonBM03/index.html), 

and only two of these sites (JUCTION and X 123) are within 

the Long Valley volcanic region (fig. 1A). It is worth noting 

that the 4th site along Hwy 395 (T2SR, approximately at km 

20) and the 2nd site along Hwy 203 (PM14, approximately at 

km 5) show a suspiciously large difference between the geoids 

and can probably be considered as outliers. These outliers may 

reflect local anomalies in the gravity field.

The Long Valley Caldera Hybrid Geoid 

Height Model LVGEOID 

Conversion surface

Following Milbert and Smith (1996), we modeled a 

“locally adjusted” conversion surface s to improve the hybrid 

geoid for Long Valley Caldera. As a first step, we computed 

the conversion surface s at the colocated sites (table 4)

s = h83 – N03 - H88, (8)

where N03 is the gravimetric geoid USGG2003 height. Then 

we interpolated the “locally corrected” conversion surface s

at sites where we have no direct measurements. Finally, we 

estimated the interpolation error (see appendix for details). We 
The Long Valley Caldera Hybrid Geoid Height Model LVGEOID 7

A) Hwy 395

-25.2

-25.0

-24.8

-24.6

-24.4

-24.2

0 5 10 15 20 25 30 35 40 45 50 55 60 65

DISTANCE FROM C916 TO CROWLEY AZ (KM)

GEOID, IN METERS

Measured geoid

GEOID03

B) Hwy 203 - Long Valley

-25.2

-25.0

-24.8

-24.6

-24.4

-24.2

0 5 10 15 20 25 30 35 40 45

DISTANCE FROM RET TO 4JD (KM)

GEOID, IN METERS

Measured geoid

GEOID03

outlier

outlier

Figure 3. Profiles of the measured geoid and GEOID03 along the GPS-on-Bench Mark sites in the Long Valley 

region. Hwy 395 (A) crosses Long Valley caldera from north to south (the caldera extends approximately 

between the 30 km and 50 km distances along the leveling route), whereas Hwy 203 - Long Valley (B) crosses 

Long Valley caldera from west to east. See fig. 1 for bench mark locations. The 4th site along HWY 395 (T2SR, 

approximately at km 20) and the 2nd site along Hwy 203 (PM14, approximately at km 5) show a suspiciously 

large difference between the geoids and can probably be considered as outliers.
8 Converting NAD83 GPS Heights Into NAVD88 Elevations With LVGEOID, Long Valley Volcanic Region, California

calculated the new “locally adjusted” hybrid geoid height at 

each leveling bench mark (see table 5) by adding s to the NGS 

gravimetric geoid USGG2003 (Smith and Roman, 1999). The 

stated uncertainties in the “locally corrected” hybrid geoid 

model are from the propagation of errors from interpolation only, since there is no formal accuracy estimate for the 

gravimetric geoid (Roman, NGS, written commun.). Geoid 

uncertainties average 0.022 m with a median value of 0.021 m 

and a standard deviation of 0.008 m. 

A plot of the “locally corrected” geoid LVGEOID against 

GEOID03 is shown in fig. 4, whereas the spatial distribution 

of the difference between LVGEOID and GEOID03 is shown 

in fig. 5. 

Summary and Conclusions

We have tied GPS and leveling to a common reference 

frame in the Long Valley area so that we can compute the 

vertical deformation by differencing GPS-based and leveled 

orthometric heights. To transform directly between GPS ellipsoid heights and orthometric heights, we related the gravimetric geoid height N, the ellipsoidal heights h, and the orthometric heights H through an empirical conversion surface s. 

The new geoid model N+s is called a hybrid geoid (Smith and 

Milbert, 1999). In December 2003, the National Geodetic Survey released the latest gravimetric geoid model (USGG2003) 

and hybrid geoid model (GEOID03) for the conterminous 

United States. 

We compared the NGS GEOID03 model against the 

experimental values of the geoid height measured at 25 

GPSBM sites. These sites were occupied in the summer of 

2006 by both GPS and leveling surveys. From the profiles 

shown in figure 3, we can see that although the geoid shapes 

are similar, the NGS model underestimates the geoid height 

within the caldera. The difference reaches a maximum of 18.5 

cm close to the caldera’s resurgent dome and appears negligible at Lee Vining and Tom’s Place, outside the caldera. 

We used geostatistics (ordinary kriging and Gaussian 

simulation) to estimate the new conversion surface s in the 

Long Valley region at any unsampled leveling benchmark 

from the 25 available data points. We calculated the new 

“locally adjusted” hybrid geoid height (LVGEOID) at each 

leveling bench mark (see table 5) by adding s to the NGS 

gravimetric geoid USGG2003 (Smith and Roman, 1999). The 

average LVGEOID uncertainty of 0.022 m compares well with 

the published uncertainty for GEOID03 (0.024 m). 

A quantitative check can be made by comparing the vertical displacements calculated for the intervals 1985 to 1999 

and 1985 to 2006 using the different geoid height models (fig. 

6). There are several reasons to choose these intervals – (1) 

Electronic Distance Measurement (EDM) coverage of the 

caldera began in 1985; (2) in 1999, Battaglia and others (2003) 

performed GPS surveys on Bench Marks in the Long Valley 

volcanic region; (3) the latest leveling survey was in 2006; and 

(4) continuous GPS results suggest that as little as 4 to 7 mm 

of net vertical displacement occurred from 1999 to 2006 (fig. 

7; http://quake.wr.usgs.gov/research/deformation/gps/auto/

LongValley/rdom/index.html). Although the 1999-1985 GPSleveling vertical deformation estimated using LVGEOID compares satisfactorily with the 2006-1985 leveling-leveling uplift, 

both GEOID03 and GEOID99 underestimate the GPS based 

orthometric heights for 1999, and thus the vertical deformation 

between 1999 and 1985. At the resurgent dome (the area with 

the most pronounced deformation in Long Valley Caldera), the 

deformation determined used the NGS geoid is underestimated 

by 0.10 to 0.15 m.

The geodetic data set for the 1999-85 differences (44 

height measurements, and 34 EDM baseline length changes) 

can be inverted to have an estimate of the parameters of the 

intrusion beneath the resurgent dome. A prolate spheroidal 

source is used to parameterize the horizontal and vertical 

deformation. The inversion of the data is performed using a 

weighted least square algorithm, whereas the penalty function 

minima are searched by a Nelder-Mead simplex direct search 

algorithm. A bootstrap algorithm is used to estimate the 95 

percent (two standard deviations) bounds on the parameters. 

Preliminary results (see table 6) point to a deeper, larger 

source than that previously inferred. 

Table 6. Ninty-five-percent (two standard deviations) bounds on intrusion source parameters.

GEOID99

(after Battaglia and others, 2003) LVGEOID

X (UTM) 332188 332411 332831

Y (UTM) 4172064 4171963 4172579

Depth (km) 4.9 7.6 7.2 8.2

Aspect ratio 0.25 0.65 0.52 0.64

Volume change (km3

) 0.06 0.13 0.13 0.15

§

 Dimensionless pressure: pressure change/shear modulus.
Summary and Conclusions 9

Hwy 395

-25.2

-25.0

-24.8

-24.6

-24.4

-24.2

0 10 20 30 40 50 60 70

DISTANCE FROM C916 [LEE VINING] TO F124 [TOM'S PLACE], IN KILOMETERS

GEOID HEIGHT MODEL, IN METERS GEOID HEIGHT MODEL, IN METERS

LVGEOID (m) GEOID03 measured geoid

caldera

Hwy 203

-25.2

-25.0

-24.8

-24.6

-24.4

-24.2

0 5 10 15 20

FROM RET TO CASA AZ, IN KILOMETERS

Big Loop

-25.2

-25.0

-24.8

-24.6

-24.4

-24.2

0 10 20 30

FROM B13 TO 8DOR [OWENS RIVER RD], IN KILOMETERS

GEOID HEIGHT MODEL, IN METERS

Small Loop

-25.2

-25.0

-24.8

-24.6

-24.4

-24.2

0 5 10 15 20

FROM 13DOR TO 3EGE [RES. DOME], IN KILOMETERS

Crowley Lake

-25.2

-25.0

-24.8

-24.6

-24.4

-24.2

0 5 10 15 20 25

FROM KWH4 TO TBMLC4, IN KILOMETERS

Figure 4. Geoid height profiles from leveling surveys in the Long Valley region. The two outliers are benchmarks T2SR 

(Hwy 395) and PM14 (Hwy 203).
10 Converting NAD83 GPS Heights Into NAVD88 Elevations With LVGEOID, Long Valley Volcanic Region, California

C916

JUCTION

BM7

Mono

Lake

Glass Mt

Long Valley caldera

Mono Domes

Crowley

Lake

Inyo Craters

Mammoth

Mt

X123

EAL15

D916

13DOR

RET

5JCM

2JCM

A124R

CONVICT

V911

D124

CROWLEY

1EGE

18EGE

25EGE

KWH6

25JCM

26JCM

44DOR

29JCM

T3SR

4JD

K1383

0 5 10 KILOMETERS

LVGEOID - GEOD03, IN METERS

-0.185 - -0.150

-0.150 - -0.115

-0.115 - -0.080

-0.080 - -0.045

-0.045 - -0.010

-0.010 - -0.025

NO DATA

LEVELING ROUTES

Antelope V.

Big Loop

Hwy 203

Hwy 395

Small Loop

Other Loop

Long Valley Loop

GPSBM 2006

Figure 5. Map of the difference between LVGEOID and the GEOID03 NGS geoid height model in the Long Valley region.
Summary and Conclusions 11

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0 10 20 30 40 50 60

DISTANCE FROM LEE VINING, IN KILOMETERS

UPLIFT, IN METERS

-0.2

-0.1

0.0

0.1

0.2

0.3

0.4

0 10 20 30 40 50 60

DISTANCE FROM MAMMOTH MT, IN KILOMETERS

UPLIFT, IN METERS

Hwy 395

Hwy 203 - LONG VALLEY

2006-1985

99-85, LVGEOID

99-85, GEOID03

99-85, GEOID99

Figure 6. Vertical deformation in the Long Valley region measured along the two leveling routes occupied in the summer of 2006. 

2006-1985 is the deformation computed by differencing the 2006 and 1985 leveling surveys. The other three lines show the deformation 

between 1999 and 1985 obtained differencing the 1999 GPS based orthometric heights and the 1985 leveled orthometric heights. 

LVGEOID, GEOID03, and GEOID99 are the three geoid height models employed to compute the GPS based orthometric heights.
12 Converting NAD83 GPS Heights Into NAVD88 Elevations With LVGEOID, Long Valley Volcanic Region, California

-80

-60

-40

-20

0

20

40

60

80

1999 2000 2001 2002 2003 2004 2005 2006 2007

Year

RDOM UP, IN MILLIMETERS

Figure 7. Vertical deformation at the permanent GPS site RDOM in Long Valley Caldera. The site is on 

the caldera resurgent dome (see also fig. 1A). Vertical velocity is 0.6 to 1.0 mm/yr. In the 7 years between 

the 1999 GPS ellipsoid heights on leveled on bench marks (GPS-on-Bench Mark) and the 2006 GPS 

and leveling surveys, the expected deformation is on the order of 4 to 7 mm (http://quake.wr.usgs.gov/

research/deformation/gps/auto/LongValley/rdom/index.html).

Acknowledgments

Comments from J. Murray and M. Poland greatly helped 

to improve the manuscript.

References Cited

Balazs, E.I., Young, G.M., 1982, Corrections applied by the 

National Geodetic Survey to precise leveling observations: 

National Oceanic and Atmospheric Administration Technical Memorandum, NOS-NGS 34, 12 p.

Battaglia, M., Segall, P., Murray, J., Cervelli, P. and Langbein, 

J. 2003, The mechanics of unrest at Long Valley caldera, 

California; 1-Modeling the geometry of the source using 

GPS, leveling and 2-color EDM data: Journal of Volcanology and Geothermal Research, v. 127, p. 195-217

Goovaerts, P., 1997, Geostatistics for Natural resources Evaluation: Oxford University Press, New York, N.Y.

Heiskanen, W., and Moritz, H., 1967, Physical Geodesy. W.H. 

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Kotsakis, C., and Sideris, M.G., 1999. On the adjustment of 

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Langbein, J., Dzurisin, D., Marshall, G., Stein, R., and Rundle, 

J., 1995, Shallow and peripheral volcanic sources of infla Shallow and peripheral volcanic sources of inflation revealed by modeling two-color geodimeter and leveling data from Long Valley Caldera, California, 1988-1992: 

Journal of Geophysical Research, v. 100, p. 12487-12495.

Langley, R.B., 1992, Basic geodesy for GPS: GPS World, v. 

92, p. 44-49.

Lichten, S.M., and Border, J.S., 1987, Strategies for highprecision global positioning system orbit determination: 

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Milbert, D.G., 1998, Documentation for the GPS Benchmark 

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Service, Milan, p. 29-42.

Milbert, D.G., 1995, Improvement of a high resolution 

geoid height model in the United States by GPS height on 

NAVD88 bench marks-New geoids in the world: Bulletin d’Information, Bureau Gravimetrique International 

0373-9023, v. 77, p. 13-36.
Appendix. Geostatistical Analysis 13

FREQUENCY

s, IN METERS

-.200 -.100 .000 .100

.000

.100

.200

.300

.400

Conversion surface

Number of data 25

Mean -.08

Standard deviation .04

Figure 8. Histogram of the conversion surface. Compare 

this non-Gaussian distribution with the normal distribution in 

figure 10 obtained through the transformation described in the 

accompanying text.

Milbert, D.G., and Smith, D.A., 1996, Converting GPS Height 

into NAVD 88 Elevation with the GEOID96 Geoid Height 

Model; GIS/LIS ’96 Annual Conference and Exposition: 

American Congress on Surveying and Mapping, Washington, D.C., p. 681-692.

Prescott, W.H., J.C. Savage, J.L. Svarc, and Manaker, D., 

2001, Deformation across the Pacific-North America 

plate boundary near San Francisco, California: Journal of Geophysical Research, v. 106, B4, p. 6673-6682, 

10.1029/2000JB900397. 

Rapp, R.H., 1980, Precise definition of the geoid and its 

realization for vertical datum applications: Proceedings 2nd

International Symposium on Problems Related to the Redefinition of North American Vertical Geodetic Networks, the 

Canadian Institute of Surveying, Ottawa, p. 73-86.

Roman, D.R., Wang, Y.M., Henning, W., and Hamilton, 

J., 2004, Assessment of the New National Geoid Height 

Model, GEOID03: Proceedings of the 2004 ACSM/TAPS 

Conference and Technology Exhibition, Nashville, Tenn., 

April 16-21, 2004.

Smith, D.A., 1998, There is no such thing as “The” EGM96 

geoid-Subtle points on the use of a global geopotential 

model: Bulletin no. 8, International Geoid Service, Milan, 

1998, p. 17-28.

Smith, D., and Milbert, D.G., 1999, The GEOID96 high-resolution geoid height model for the United States: Journal of 

Geodesy, v. 73, p. 219-236.

Snay, A., and Soler, T., 2000, Modern Terrestrial reference 

Systems, part 3: WGS84 and ITRS. Professional Survey, v. 

3, p. 1-3.

Wdowinski, S., Bock, Y., Zhang, J., Fang, P.,and Genrich J., 

1997, Southern California Permanent GPS Geodetic Array: 

Spatial Filtering of Daily Positions Estimating Coseismic 

and Postseismic Displacements Induced by the 1992 Landers Earthquake: Journal of Geophysical Research, v. 102, p. 

18057-18070.

Zilkoski, D.B., Richards, J.H., and Young, G.M., 1992, 

Results of the general adjustment of the North American 

Vertical datum of 1988: Surveying and Land Information 

Systems, v. 52, p. 133-149.

Zumberge, J.F., Heflin, M.B., Jefferson, D.C., Watkins, M.M., 

and Webb, F.H., 1997, Precise point positioning for the efficient and robust analysis of GPS data from large networks: 

Journal of Geophysical Research. v. 102, p. 5005-5017.

Appendix. Geostatistical Analysis

Spatial Interpolation

We used ordinary kriging, a linear least-square regression 

algorithm, to estimate the experimental conversion surface s 

at unsampled leveling benchmarks (Goovaerts, 1997, p. 132). 

The geostatistical analysis and interpolation was carried out 

using the geostatistical software library GSLIB (Deutsch and 

Journel, 1998; http://www.gslib.com/). Kriging interpolates the 

value of the continuous attribute s at any unsampled locations 

u using only the values of s available over our study area, the 

data s(uα) (see 8 and table 4). 

The linear estimator is defined as

u u u u u [ ]

( )

1

( ) ( ) ( ) ( ) ( )

n

s m s m =

u

– ∑ – α

λ α α α , (9)

where λα(u) is the weight assigned to the datum s(uα), 

and the quantities m(u) and m(uα) are the expected values 

(means) of s(u) and s(uα). The number of data involved in 

the estimation, as well as their weights, may change from one 

location to another. In practice, only the n(u) data within a 
14 Converting NAD83 GPS Heights Into NAVD88 Elevations With LVGEOID, Long Valley Volcanic Region, California

given neighborhood W(u), centered on the location u being 

estimated, are retained. Ordinary kriging accounts for local 

fluctuations of the mean assuming that m(u) is constant, but 

unknown, within W(u) (Goovaerts, 1997, p. 126). It is well 

known that kriging smoothes the fit of a curve or surface to 

data and that the histogram of the values estimated by kriging 

will display more values around the mean but less extreme 

values than the histogram of the observations (for example, 

Biau and others, 1999). 

The key function in the interpolation is the variogram 

λα(u). The variogram describes the spatial dependence of s, 

and is used to calculate the weights λα(u) and the mean m(u) 

applied in . Typically, the variogram function is inferred and 

modeled from the experimental variogram computed from 

the experimental data (Goovaerts, 1997, p. 82; fig. 9). Variogram models can be divided into two types; those that reach a 

plateau (called a “sill”, and designated as c) and those that do 

not. The distance at which they reach this plateau is called the 

“range,” a. The variogram discontinuity at the origin is called 

the “nugget effect,” n. More than one theoretical model can fit 

the experimental variogram (fig. 9). 

We choose the best model using cross-validation (Isaaks 

and Srivastava, 1989, ch. 15). In cross-validation, actual 

data points are dropped one at a time and re-estimated using 

0

1

2

3

0 6 12 18 24 30 36 42 48 54

DISTANCE H, IN KILOMETERS

VARIOGRAM

 Experimental

 Hole

 Power

Figure 9. The conversion surface variogram inferred from the 

25 measured values. Hole effect model defined by a length a to 

the first peak and positive variance contribution c. Power model 

defined by a power 0 2 ω< < and positive slope c. n is the 

nugget effect (Deutsch and Journel, 1998, p. 28). 

· Hole (a, c, n: 18.2112 1.0403 0.1794) - 

γ H ( ) 1 cos h c = ⋅ − ⎡ ( ) π h a ⎤ ⎣ ⎦

· Power (ω, c, n: 0.0399 1.3382 0.0122) - 

( ) P h c hω γ = ⋅

Table 7. Cross-validation of the variogram model for the 

conversion surface.

Data Power model Hole model

Mean -0.0845 -0.0893 -0.0868

Standard deviation 0.0449 0.0419 0.0409

Correlation 0.8269 0.7221

the remaining neighboring data. Each datum is replaced in 

the data set once it has been re-estimated. We accepted the 

model with the highest correlation between true and estimated 

values (the power model for the conversion surface, see table 

7). Although cross-validation can detect possible problems, 

it does not ensure that the interpolation will give “realistic” 

results (Journel, 1989). We report the interpolated values in 

table 5.

Assessment of Spatial Uncertainty

A by-product of kriging is the kriging variance, which is 

dependent on the variogram model and the data configuration, 

and is independent of the data values. Thus, given a variogram model, two identical data configurations would yield the 

same kriging variance no matter what the data were. In this 

sense, the kriging variance is only a ranking index of the data 

geometry and size (that is, the kriging variance increases when 

the location u being estimated gets farther away from the data 

location uα)-not a measure of the local spread of errors (Goovaerts 1997, p. 179).

The smoothing effect of kriging on the interpolation is 

due to a missing error component. Consider the variable S(u) 

as the sum of the estimator s(u) and the corresponding error 

r(u)

S(u) = s(u) + r(u)

The kriging equation would provide the smoothly 

varying estimator s(u). To restore the full variance of our 

geostatistical model, one may think of simulating a realization of the error with zero mean and the correct variance and 

variogram (Deutsch and Journel, 1998, p. 127). The simulated 

value of the variable would be the sum of the unique estimate 

and a simulated error value

s(s)(u) = s(u) + r(s)(u)

We applied a sequential Gaussian simulation algorithm to 

simulate the variable of interest s (Deutsch and Journel, 1998, 

p. 127). The standard deviation of the simulated variable is 

taken as measure of the interpolation error (Battaglia and others, 2003). 

γ
Appendix. Geostatistical Analysis 15

The Gaussian simulation works with data that follow a 

normal distribution. Even though most Earth science data do 

not follow a normal distribution, a nonlinear transformation 

can convert the original data distribution (fig. 8) into a normal 

distribution (fig. 10). The transformed data set is also called 

“normal score.” The simulation is performed in the normal 

space and repeated 500 times, and all the simulated values 

are back-transformed (Deutsch and Journel, 1998, p. 141). At 

any sampled point, the simulation algorithm returns the exact 

experimental value.

Just as in kriging, the variogram model is the key to any 

Gaussian simulation. Two models (hole and gaussian) fit the 

experimental normal score variogram (fig. 11). Although 

cross-validation (table 8) indicates that two models have 

practically identical performances, a statistical analysis of the 

simulation shows that the gaussian model better reproduces 

the overall statistics of the experimental data (fig. 10).

Figure 10. Histograms of the conversion surface (normal score) and the simulations. The gaussian model best reproduces the 

overall statistics of the normal score data set. The number of simulation data corresponds to 500 realizations of the conversion 

surface (normal score) on a grid of 190x235 cells, covering the Long Valley region from Lee Vining to Tom’s Place. Each cell is 

0.2x0.2 km in size. 

Figure 11. The normal score variogram inferred from the 25 

measured values. Hole effect model defined by a length a to 

the first peak and positive variance contribution c; Gaussian 

model defined by an effective range a and a positive variance 

contribution c; and n is the nugget effect (Deutsch and Journel, 

1998, p. 28). 

· Hole (a, c, n: 19.5746 0.8188 0.2543 - 

γ H ( ) 1 cos h c = ⋅ − ⎡ ( ) π h a ⎤ ⎣ ⎦

· Gaussian (a, c, n: 34.3768 1.6947 0.1340) - 

· Note that Gaussian model fit the data only for a limited 

distance. This is not a problem, because the best variogram model is chosen by cross-validation (see fig. 10).

FREQUENCY

VALUE

-2.2 0 -1.2 0 -.2 0 .8 0 1.80 2.80 3.80 4.80

.000

.100

.200

.300

.400

.500 Simulation (gaussian model)

Number of Data Mean

Standard deviation

coef. of var

Maximum

Upper quartile

median

Lower quartile

Minimum

22325000

.33

1.02

undefined

5.38

.39

-.03

-.54

-5.85

FREQUENCY

VALUE

-2.2 0 -1.2 0 -.2 0 .8 0 1.80 2.80 3.80 4.80 .000

.050

.100

.150

.200

.250

Simulation (hole model)

Number of Data

Mean

Standard deviation

coef. of var

Maximum

Upper quartile

Median

Lower quartile

Minimum

22325000

21.37

300.78

undefined

55412.90

.64

-.17

-1.21

-82860.41

FREQUENCY

-2.2 0 -1.2 0 -.2 0 .8 0 1.80 2.80 3.80 4.80 .000

.100

.200

.300

Conversion surface (normal score)

Number of Data Mean

Standard deviation coef. of var

Maximum Upper quartile Median

Lower quartile Minimum

25

.00

.97

undefined

2.05

.68

.00

-.68

-2.05

VALUE

0

1

2

3

0 6 12 18 24 30 36 42 48 54

DISTANCE H, IN KILOMETERS

VARIOGRAM 

 Experimental

 Hole

 Gaussian

Table 8. Cross-validation of the variogram model the normal 

score.

Data Gaussian model Hole model

Mean -0.0000 -0.0466 -0.0394

Standard deviation 0.09951 0.8715 0.8913

Correlation 0.5922 0.6011

( ) 2 2 ( ) 1 exp 9 P γ h c = ⋅ − − ⎡ h a ⎤ ⎣ ⎦

γ
Tables 1–5
Table 1. Leveling heights for the Long Valley region (see fig. 1B for bench mark locations)—Continued.BM ID Distance

NAD 27 NAD 83 2006 leve

LAT (°) W LONG (°) X (UTM) Y (UTM) LAT (°) LONG (°) raw o

Hw 395

C916 0 37.945556 119.103889 315132 4201661 37.94553 -119.10488 2072.542 20

U123 1.18 37.934444 119.101111 315350 4200413 37.93433 -119.10208 2066.386 20Q916 4.67 37.906389 119.094444 315869 4197293 37.90633 -119.09538 2081.839 20DIABLO 5.87 37.895000 119.091944 316060 4196023 37.89493 -119.09288 2093.084 20V123 6.71 37.888611 119.091944 316045 4195313 37.88853 -119.09288 2091.156 20JUCTION 7.22 37.886667 119.089722 316233 4195097 37.88663 -119.09068 2101.939 21W123 RESET 9.72 37.863333 119.086944 316421 4192495 37.86323 -119.08788 2155.200 21N916 11.07 37.853333 119.082778 316757 4191378 37.85323 -119.08378 2190.014 21BM7 12.29 37.842500 119.077500 317197 4190169 37.84243 -119.07848 2220.981 22M916 13.87 37.831389 119.070833 317759 4188924 37.83133 -119.07178 2273.714 225 RESET 16.66 37.811111 119.050833 319470 4186632 37.81103 -119.05178 2351.603 23J916 20 37.804167 119.037500 320624 4185841 37.80413 -119.03848 2403.222 2416DOR 20.44 37.790000 119.029444 321303 4184250 37.78993 -119.03038 2421.198 24K916 21.9 37.780000 119.019444 322160 4183121 37.77993 -119.02038 2437.253 24T2SR 21.91 322099 4183201 37.78064 -119.02109 2436.417 24BM2 23.43 37.770833 119.007778 323160 4182078 37.77073 -119.00878 2450.858 24B1391 24.18 37.766667 119.001667 323687 4181612 37.76663 -119.00268 2420.170 24A1391 24.64 37.763333 118.998056 323996 4181228 37.76323 -118.99908 2394.960 23B1383 25.6 37.759722 118.989444 324754 4180812 37.75963 -118.99038 2354.398 23CAL TRAN88 27.43 37.752222 118.979722 325591 4179962 37.75213 -118.98068 2285.610 22A1383 27.76 37.744444 118.976389 325864 4179090 37.74433 -118.97738 2280.117 22X123 28.29 37.740278 118.973333 326127 4178629 37.74023 -118.97427 2280.484 22Z911 29.17 37.734444 118.968333 326554 4177965 37.73433 -118.96927 2292.204 22Y911 30.45 37.723056 118.960000 327259 4176696 37.72303 -118.96097 2343.482 23B13 31.57 37.715833 118.953889 327780 4175875 37.71573 -118.95487 2332.277 23EAL15 32.37 37.709167 118.950833 328038 4175137 37.70913 -118.95177 2306.170 23EAL33 32.99 37.704444 118.949722 328124 4174602 37.70433 -118.95067 2320.826 23D916 33.09 37.703056 118.950000 328095 4174459 37.70303 -118.95097 2312.192 23Z1382 RESET 33.96 37.696667 118.946667 328371 4173742 37.69663 -118.94767 2323.264 23Y123 34.91 37.689167 118.941389 328821 4172901 37.68913 -118.94237 2315.532 2313DOR 35.25 37.688056 118.938333 329092 4172773 37.68803 -118.93927 2310.754 2312DOR 36.27 37.680278 118.932778 329559 4171897 37.68023 -118.93377 2311.056 23BM12 37.33 37.671111 118.930833 329714 4170873 37.67103 -118.93177 2309.546 23W911 38.81 37.660556 118.925833 330131 4169699 37.66053 -118.92677 2242.584 221EGE 39.12 37.657222 118.923889 330291 4169318 37.65713 -118.92487 2233.810 22

Table 1. Leveling heights for the Long Valley region (see fig. 1B for bench mark locations).
Table 1. Leveling heights for the Long Valley region (see fig. 1B for bench mark locations)—Continued. BM ID Distance NAD 27 NAD 83 2006 leve

LAT (°) W LONG (°) X (UTM) Y (UTM) LAT (°) LONG (°) raw o

2EGE 39.42 37.655000 118.922778 330383 4169072 37.65493 -118.92377 2230.182 22

3EGE 39.73 37.652500 118.921111 330527 4168791 37.65243 -118.92207 2230.089 224EGE 40.03 37.650556 118.919444 330673 4168578 37.65053 -118.92037 2232.357 225EGE 40.33 37.648056 118.917222 330862 4168296 37.64803 -118.91817 2238.275 226EGE 40.6 37.646667 118.915000 331052 4168137 37.64663 -118.91597 2235.115 22Z123 40.79 37.645833 118.913333 331200 4168034 37.64573 -118.91427 2221.979 227EGE 41.04 37.644722 118.910833 331419 4167907 37.64463 -118.91177 2216.631 22CASA AZ 41.27 37.643611 118.908056 331654 4167780 37.64353 -118.90907 2209.634 22DBR11 41.35 37.643889 118.908333 331637 4167814 37.64383 -118.90927 2209.989 22DBR8 41.53 37.643056 118.906111 331830 4167721 37.64303 -118.90707 2208.597 22DBR7 41.59 37.642778 118.905556 331873 4167687 37.64273 -118.90657 2208.757 22DBR6 41.65 37.642222 118.905000 331925 4167620 37.64213 -118.90597 2207.724 22DBR5 41.82 37.642222 118.904444 331978 4167619 37.64213 -118.90537 2207.446 22DBR2 42 37.641389 118.902778 332117 4167527 37.64133 -118.90377 2201.828 22DBR1 42.05 37.641111 118.902500 332143 4167493 37.64103 -118.90347 2198.549 229EGE 42.14 37.641944 118.902500 332145 4167582 37.64183 -118.90347 2205.811 22MGB20 42.68 37.639722 118.897500 332581 4167329 37.63963 -118.89847 2193.343 21MGB19 42.73 37.639444 118.896667 332651 4167294 37.63933 -118.89767 2193.317 21MGB18 42.78 37.639444 118.896389 332677 4167294 37.63933 -118.89737 2192.796 2111EGE 42.83 37.639167 118.895833 332730 4167270 37.63913 -118.89677 2192.376 21MGB13 43.12 37.637778 118.893056 332965 4167110 37.63773 -118.89407 2190.744 2110DOR 44.96 37.632778 118.875278 334524 4166524 37.63273 -118.87626 2174.661 21A124 RESET 46.04 37.629444 118.863333 335576 4166125 37.62933 -118.86426 2168.642 21S911 RESET 47.53 37.625833 118.848333 336892 4165700 37.62573 -118.84926 2174.444 219DOR RESET 48.38 37.623333 118.838611 337742 4165406 37.62323 -118.83956 2165.434 21T911 RESET 49.11 37.620833 118.830833 338425 4165115 37.62073 -118.83176 2158.041 218DOR 50 37.618611 118.822222 339180 4164856 37.61853 -118.82316 2145.381 21CONVICT 51.16 37.614722 118.810000 340248 4164402 37.61463 -118.81096 2150.912 217DOR 52.54 37.603611 118.803611 340789 4163160 37.60353 -118.80456 2099.466 21V911 53.87 37.593889 118.794444 341581 4162068 37.59383 -118.79536 2087.225 206DOR 55.35 37.586111 118.783333 342545 4161184 37.58603 -118.78426 2108.880 21U911 56.23 37.581667 118.770278 343683 4160674 37.58163 -118.77126 2108.727 21D124 57.99 37.573056 118.758889 344672 4159701 37.57303 -118.75986 2112.663 21C1433 60.29 37.561944 118.738611 346442 4158425 37.56183 -118.73956 2142.561 21E124 61.49 37.564167 118.725556 347595 4158659 37.56413 -118.72656 2196.710 21P911 RESET 62.79 37.556111 118.716111 348418 4157745 37.55603 -118.71706 2149.444 21
Table 1. Leveling heights for the Long Valley region (see fig. 1B for bench mark locations)—Continued.BM ID Distance

NAD 27 NAD 83 2006 leve

LAT (°) W LONG (°) X (UTM) Y (UTM) LAT (°) LONG (°) raw o

CROWLEY AZ 64.05 37.558611 118.702222 349651 4158000 37.55853 -118.70316 2133.982 21

F124 64.67 37.560278 118.696111 350193 4158179 37.56023 -118.69706 2134.573 21Hw 203

CASA AZ 41.27 37.643611 118.908056 331654 4167780 37.64353 -118.90907 2209.634 22

DBR15 41.53 37.642778 118.910556 331432 4167696 37.64273 -118.91157 2215.042 22DBR16 41.58 2218.106 22DBR17 41.63 37.642222 118.911389 331360 4167631 37.64213 -118.91237 2220.713 22DBR19 41.77 37.641944 118.913056 331209 4167601 37.64183 -118.91407 2227.385 22DBR20 41.82 37.641667 118.913889 331138 4167580 37.64163 -118.91487 2229.134 22DBR21 41.86 37.641389 118.914444 331093 4167548 37.64133 -118.91537 2230.209 221LRM 42.48 37.640000 118.920556 330543 4167404 37.63993 -118.92157 2239.175 2234EGE 42.58 37.640278 118.921111 330500 4167438 37.64023 -118.92207 2242.761 2235EGE 43.6 37.639167 118.932222 329518 4167336 37.63913 -118.93317 2288.375 2236EGE 43.88 37.639167 118.935000 329271 4167341 37.63913 -118.93597 2300.971 2337EGE 44.22 37.640000 118.938611 328955 4167436 37.63993 -118.93957 2316.878 2338EGE 44.43 37.640833 118.940278 328807 4167528 37.64073 -118.94127 2326.490 232JCM 44.68 37.641667 118.940278 328809 4167628 37.64163 -118.94127 2331.964 2339EGE 44.98 37.643056 118.945278 328371 4167792 37.64303 -118.94627 2332.273 233LRM 45.79 37.646111 118.953056 327689 4168140 37.64603 -118.95407 2357.627 23STA907 45.88 37.646111 118.953611 327645 4168141 37.64603 -118.95457 2357.469 233JCM 46.4 37.647500 118.958611 327207 4168305 37.64743 -118.95957 2373.041 23K1383 47.49 37.648333 118.970556 326150 4168416 37.64823 -118.97157 2395.076 23J1383 48.54 37.648611 118.981944 325154 4168470 37.64854 -118.98287 2444.373 24H1383 49.39 37.653611 118.986944 324725 4169034 37.65353 -118.98787 2473.767 245JCM 49.95 37.656111 118.991389 324334 4169320 37.65603 -118.99237 2505.020 25G1383 50.69 37.653611 118.994167 324081 4169048 37.65354 -118.99517 2545.448 25F1383 51.42 37.650556 118.999167 323633 4168725 37.65054 -119.00017 2582.893 256JCM 51.6 37.651667 119.000278 323538 4168849 37.65164 -119.00127 2596.167 25E1383 52.27 37.650833 119.006667 322971 4168761 37.65074 -119.00767 2632.094 267JCM 52.82 37.648056 119.010833 322603 4168469 37.64804 -119.01177 2654.897 268JCM 53.85 37.650000 119.021667 321646 4168701 37.64994 -119.02267 2690.411 26JEE17 55.07 37.653333 119.032778 320675 4169088 37.65324 -119.03377 2688.590 26PM14 55.57 320472 4168980 37.65222 -119.03604 2705.347 279JCM 55.66 37.651667 119.037778 320230 4168920 37.65164 -119.03877 2715.027 27PM15 55.77 2724.494 2742EGE 56.88 37.651667 119.050833 319083 4168945 37.65164 -119.05177 2759.282 27
Table 1. Leveling heights for the Long Valley region (see fig. 1B for bench mark locations)—Continued. BM ID Distance NAD 27 NAD 83 2006 leve

LAT (°) W LONG (°) X (UTM) Y (UTM) LAT (°) LONG (°) raw o

D1383 57.68 37.654167 119.056667 318568 4169234 37.65414 -119.05767 2796.339 27

20JD 57.73 37.654167 119.056944 318551 4169234 37.65414 -119.05787 2796.461 27RET 58.11 37.656667 119.059722 318310 4169517 37.65664 -119.06067 2823.587 28Antelope Valley Rd 3EGE 39.73 37.652500 118.921111 330527 4168791 37.65243 -118.92207 2230.089 2212EGE 40.01 37.654167 118.918611 330752 4168976 37.65413 -118.91957 2236.042 2213EGE 40.28 37.651944 118.916111 330967 4168716 37.65183 -118.91707 2249.094 2224JCM 40.55 37.654167 118.914722 331096 4168969 37.65413 -118.91567 2272.126 2214EGE 40.96 37.655833 118.914444 331126 4169146 37.65573 -118.91537 2276.599 2215EGE 41.27 37.657500 118.911111 331421 4169328 37.65743 -118.91207 2289.307 2216EGE 41.95 37.660000 118.909722 331550 4169603 37.65993 -118.91067 2307.087 2323JCM 42.01 37.664167 118.906667 331824 4170064 37.66413 -118.90767 2328.435 2317EGE 42.27 37.664167 118.906667 331824 4170064 37.66413 -118.90767 2338.736 2318EGE 42.67 37.666111 118.906389 331855 4170274 37.66603 -118.90737 2327.664 2319EGE 42.96 37.668889 118.904167 332055 4170581 37.66883 -118.90517 2330.719 2320EGE 43.22 37.671389 118.903611 332114 4170857 37.67133 -118.90457 2336.381 2322JCM 43.83 37.673333 118.902500 332215 4171066 37.67323 -118.90347 2340.491 2322EGE 44.14 37.674722 118.899722 332465 4171216 37.67463 -118.90067 2340.094 2323EGE 44.53 37.675000 118.897222 332687 4171245 37.67493 -118.89817 2343.340 2321JCM 44.83 37.674167 118.893889 332976 4171150 37.67413 -118.89487 2326.433 2324EGE 45.23 37.673333 118.890556 333265 4171045 37.67323 -118.89157 2320.305 2325EGE 45.57 37.673611 118.886944 333592 4171071 37.67353 -118.88787 2301.172 2326EGE 45.94 37.676111 118.886667 333615 4171348 37.67603 -118.88767 2279.865 2227EGE 46.27 37.679167 118.885833 333701 4171691 37.67913 -118.88677 2256.428 22KWH5 47.12 37.679167 118.877778 334407 4171677 37.67913 -118.87877 2198.973 22KWH6 47.17 37.679167 118.877222 334460 4171676 37.67913 -118.87817 2199.125 2218JCM RESET 47.75 37.681944 118.871944 334933 4171966 37.68183 -118.87287 2202.042 2225JCM 49.36 37.687222 118.858889 336091 4172531 37.68713 -118.85987 2211.396 2226JCM 50.99 37.683611 118.841389 337627 4172101 37.68353 -118.84237 2157.287 2127JCM 52.3 37.679722 118.828333 338774 4171646 37.67963 -118.82927 2128.954 2128JCM RESET 53.19 37.676667 118.819167 339570 4171297 37.67663 -118.82016 2122.305 2143DOR 54.49 37.684167 118.810556 340344 4172115 37.68413 -118.81156 2111.871 2144DOR 55.79 37.675000 118.805833 340748 4171086 37.67493 -118.80676 2120.750 2129JCM 55.85 37.675000 118.805278 340792 4171085 37.67493 -118.80626 2123.125 21Long Valley

43DOR 54.49 37.684167 118.810556 340344 4172115 37.68413 -118.81156 2111.871 21
Table 1. Leveling heights for the Long Valley region (see fig. 1B for bench mark locations)—Continued.BM ID Distance

NAD 27 NAD 83 2006 leve

LAT (°) W LONG (°) X (UTM) Y (UTM) LAT (°) LONG (°) raw o

44DOR 55.79 37.675000 118.805833 340748 4171086 37.67493 -118.80676 2120.750 21

29JCM 55.879 37.675000 118.805278 340792 4171085 37.67493 -118.80626 2123.125 2149DOR 57.094 37.685556 118.798333 341432 4172249 37.68553 -118.79926 2117.673 21T3S R29E 58.191 37.687500 118.789167 342238 4172445 37.68743 -118.79016 2098.894 213JD 58.359 37.688333 118.787778 342363 4172531 37.68823 -118.78876 2108.117 2150DOR 59.832 37.687778 118.772778 343685 4172450 37.68773 -118.77376 2080.458 204JD 61.963 37.699444 118.762222 344644 4173720 37.69933 -118.76316 2077.896 20
ITRF00 NAD

BM ID X (m) Y (m) Z (m) LAT (dms) LONG (dms) height (m) σ (m) LAT (dd) LONG (dd) 

Hw 395 C916 -2450419.145 -4401717.603 3901862.070 37 56 40.7939 -119 6 16.2618 2048.888 0.018 37.94466 -119.10450 

JUCT -2451311.907 -4405770.894 3896805.613 37 53 12.2367 -119 5 27.5163 2078.324 0.018 37.88673 -119.09096 

BM07 -2451833.960 -4409032.959 3893006.686 37 50 33.2118 -119 4 41.3230 2197.436 0.013 37.84255 -119.07813 

T2SR -2449570.806 -4415305.648 3887707.705 37 46 50.3230 -119 1 15.9916 2412.830 0.015 37.78064 -119.02109 

X123 -2447236.056 -4419592.030 3884073.818 37 44 25.2129 -118 58 27.7323 2256.680 0.017 37.74033 -118.97436 

EA15 -2446539.834 -4422417.572 3881355.677 37 42 33.1483 -118 57 7.0136 2282.240 0.018 37.70920 -118.95193 

D916 -2446675.900 -4422826.693 3880817.210 37 42 10.9301 -118 57 3.7904 2288.246 0.018 37.70303 -118.95104 

13DO -2446236.824 -4424196.403 3879538.797 37 41 18.5810 -118 56 21.0628 2286.816 0.019 37.68849 -118.93917 

1EGE -2446147.210 -4426593.686 3876751.808 37 39 26.3398 -118 55 30.5551 2209.887 0.021 37.65731 -118.92514 

A124 -2442387.554 -4430783.175 3874244.940 37 37 45.3173 -118 51 53.7879 2144.692 0.018 37.62925 -118.86493 

CONV -2438694.463 -4433914.285 3872968.372 37 36 53.5008 -118 48 40.3435 2126.971 0.013 37.61486 -118.81119 

V911 -2438236.020 -4435715.037 3871102.288 37 35 38.7132 -118 47 48.6101 2063.397 0.020 37.59408 -118.79682 

D124 -2436073.169 -4438579.376 3869234.977 37 34 21.6729 -118 45 35.1857 2088.882 0.012 37.57268 -118.75976 

CROA -2432179.496 -4441819.302 3868009.583 37 33 31.0159 -118 42 12.6637 2110.124 0.020 37.57268 -118.75976 

Hw 203 2JCM -2448139.275 -4426795.549 3875434.378 37 38 29.9317 -118 56 37.6672 2308.123 0.018 37.64164 -118.94378 

K138 -2450061.872 -4425273.250 3876057.839 37 38 53.8817 -118 58 16.3161 2371.290 0.026 37.64830 -118.97118 

5JCM -2451481.682 -4423984.601 3876807.417 37 39 21.8251 -118 59 32.4275 2481.347 0.042 37.65606 -118.99233 

PM14 -2455059.681 -4422479.395 3876592.227 37 39 8.0001 -119 2 9.7977 2681.712 0.020 37.65222 -119.03604 

RETT -2456867.244 -4421287.068 3876999.297 37 39 21.7108 -119 3 37.8439 2800.002 0.013 37.65603 -119.06050 

Antelope Valley Rd 18EG -2444518.478 -4426901.440 3877576.656 37 39 57.7769 -118 54 26.3383 2303.678 0.029 37.66605 -118.90730 

25EG -2442785.387 -4427263.227 3878207.757 37 40 24.2927 -118 53 17.3162 2277.133 0.021 37.67341 -118.88813 

KWH6 -2441775.218 -4427266.572 3878668.793 37 40 45.7358 -118 52 41.1673 2175.047 0.019 37.67937 -118.87809 

25JC -2440123.372 -4427570.743 3879376.437 37 41 14.4222 -118 51 36.1584 2187.269 0.022 37.68734 -118.86003 

26JC -2438889.595 -4428453.656 3879057.484 37 41 2.7103 -118 50 34.6865 2133.127 0.019 37.68408 -118.84295 

44DO -2436384.951 -4430499.056 3878240.950 37 40 30.1741 -118 48 24.9339 2096.536 0.016 37.67504 -118.80691 

29JC -2436349.096 -4430535.028 3878226.400 37 40 29.5184 -118 48 22.9451 2098.917 0.018 37.67486 -118.80636 

Long Valley T3SR -2434676.129 -4430438.460 3879339.680 37 41 15.7376 -118 47 25.0312 2074.636 0.020 37.68770 -118.79027 

4JDD -2432186.508 -4430876.515 3880359.537 37 41 58.0532 -118 45 47.3840 2053.676 0.019 37.69946 -118.76315 

Table 2. Long Valley region GPS-on-Bench Mark survey for 2006 (http://quake.wr.usgs.gov/research/deformation/gps/auto/MammothLevel/in
Table 3. Experimental hybrid geoid height (N+s) for the Long Valley region.BM ID Distance

UTM NAVD 27 NAD83 GPS NAVD88 leveled measured geoid GEOID03 

X Y height (m) σ (m) height (m) σ (m) N+s (m) σ (m) N+s (m) σ (m) 

Hw 395

C916 0 315132 4201661 2049.495 0.018 2073.909 0.000 -24.414 0.018 -24.408 0.024 

JUCTION 7.22 316233 4195097 2078.932 0.018 2103.324 0.002 -24.392 0.018 -24.374 0.024 BM7 12.29 317197 4190169 2198.046 0.013 2222.401 0.002 -24.355 0.013 -24.364 0.024 

T2SR 21.91 322099 4183201 2413.442 0.015 2438.180 0.003 -24.738 0.015 -24.454 0.024 

X123 28.29 326127 4178629 2257.295 0.017 2281.984 0.004 -24.689 0.017 -24.624 0.024 EAL15 32.37 328038 4175137 2282.856 0.018 2307.738 0.004 -24.882 0.018 -24.750 0.024 D916 33.09 328095 4174459 2288.863 0.018 2313.766 0.004 -24.903 0.018 -24.754 0.024 13DOR 35.25 329092 4172773 2287.433 0.019 2312.335 0.004 -24.902 0.019 -24.778 0.024 1EGE 39.12 330291 4169318 2210.505 0.021 2235.359 0.004 -24.854 0.021 -24.749 0.024 A124 RESET 46.04 335576 4166125 2145.312 0.018 2170.171 0.005 -24.859 0.019 -24.723 0.024 CONVICT 51.16 340248 4164402 2127.593 0.013 2152.398 0.005 -24.805 0.014 -24.727 0.024 V911 53.87 341581 4162068 2064.020 0.020 2088.710 0.005 -24.690 0.021 -24.608 0.024 D124 57.99 344672 4159701 2089.505 0.012 2114.139 0.005 -24.634 0.013 -24.558 0.024 CROWLEY AZ 64.05 349651 4158000 2110.749 0.020 2135.442 0.006 -24.693 0.021 -24.662 0.024 

Hw 203

2JCM 44.68 328809 4167628 2308.740 0.018 2333.530 0.005 -24.790 0.019 -24.668 0.024 

K1383 47.49 326150 4168416 2371.907 0.026 2396.670 0.005 -24.763 0.026 -24.657 0.024 5JCM 49.95 324334 4169320 2481.963 0.042 2506.653 0.005 -24.690 0.042 -24.651 0.024 PM14 55.57 320472 4168980 2682.327 0.020 2707.054 0.005 -24.727 0.021 -24.593 0.024 RET 58.11 318310 4169517 2800.616 0.013 2825.176 0.005 -24.560 0.014 -24.543 0.024 

Antelope V.

18EGE 42.67 331855 4170274 2304.296 0.029 2329.226 0.005 -24.930 0.029 -24.808 0.024 

25EGE 45.57 333592 4171071 2277.751 0.021 2302.739 0.005 -24.988 0.022 -24.851 0.024 KWH6 47.17 334460 4171676 2175.665 0.019 2200.666 0.005 -25.001 0.020 -24.866 0.024 25JCM 49.36 336091 4172531 2187.888 0.022 2212.922 0.005 -25.034 0.023 -24.899 0.024 26JCM 50.99 337627 4172101 2133.746 0.019 2158.812 0.005 -25.066 0.020 -24.923 0.024 44DOR 55.79 340748 4171086 2097.156 0.016 2122.281 0.005 -25.125 0.017 -24.962 0.024 29JCM 55.85 340792 4171085 2099.537 0.018 2124.655 0.005 -25.118 0.019 -24.962 0.024 

Long Valley

T3S R29E 58.191 342238 4172445 2075.256 0.020 2100.422 0.005 -25.166 0.021 -24.981 0.024 

4JD 61.963 344644 4173720 2054.296 0.019 2079.386 0.006 -25.090 0.020 -24.959 0.024 
24 Converting NAD83 GPS Heights Into NAVD88 Elevations With LVGEOID, Long Valley Volcanic Region, California

Table 4. Experimental conversion surface s for the Long Valley region.

NAD83 GPS NAVD88 leveled USGG2003 s

BM ID height (m) σ (m) height (m) σ (m) height (m) height (m) σ (m)

Hw 395

C916 2049.495 0.018 2073.909 0.000 -24.320 -0.094 0.024

JUCTION 2078.932 0.018 2103.324 0.002 -24.299 -0.093 0.024

BM7 2198.046 0.013 2222.401 0.002 -24.300 -0.055 0.024

T2SR 1 2413.442 0.015 2438.180 0.003 -24.419 -0.319 0.024

X123 2257.295 0.017 2281.984 0.004 -24.610 -0.079 0.024

EAL15 2282.856 0.018 2307.738 0.004 -24.749 -0.133 0.024

D916 2288.863 0.018 2313.766 0.004 -24.755 -0.148 0.024

13DOR 2287.433 0.019 2312.335 0.004 -24.785 -0.117 0.024

1EGE 2210.505 0.021 2235.359 0.004 -24.767 -0.087 0.024

A124 RESET 2145.312 0.018 2170.171 0.005 -24.762 -0.097 0.024

CONVICT 2127.593 0.013 2152.398 0.005 -24.776 -0.029 0.024

V911 2064.020 0.020 2088.710 0.005 -24.663 -0.027 0.024

D124 2089.505 0.012 2114.139 0.005 -24.620 -0.014 0.024

CROWLEY AZ 2110.749 0.020 2135.442 0.006 -24.730 0.037 0.024

Hw 203

2JCM 2308.740 0.018 2333.530 0.005 -24.686 -0.104 0.024

K1383 2371.907 0.026 2396.670 0.005 -24.665 -0.098 0.024

5JCM 2481.963 0.042 2506.653 0.005 -24.652 -0.038 0.024

PM14 1 2682.327 0.020 2707.054 0.005 -24.584 -0.143 0.024

RET 2800.616 0.013 2825.176 0.005 -24.527 -0.033 0.024

Antelope V.

18EGE 2304.296 0.029 2329.226 0.005 -24.828 -0.102 0.024

25EGE 2277.751 0.021 2302.739 0.005 -24.873 -0.115 0.024

KWH6 2175.665 0.019 2200.666 0.005 -24.889 -0.112 0.024

25JCM 2187.888 0.022 2212.922 0.005 -24.925 -0.109 0.024

26JCM 2133.746 0.019 2158.812 0.005 -24.954 -0.112 0.024

44DOR 2097.156 0.016 2122.281 0.005 -25.001 -0.124 0.024

29JCM 2099.537 0.018 2124.655 0.005 -25.001 -0.117 0.024

Long Valley

T3S R29E 2075.256 0.020 2100.422 0.005 -25.021 -0.145 0.024

4JD 2054.296 0.019 2079.386 0.006 -25.001 -0.089 0.024

1

 This point is an outlier and has not been included in the final interpolation.
Tables 1–5 25

Table 5. Geoid heights at leveling benchmarks for the Long Valley region (see fig. 1B for benchmark location)—Continued.

BM

UTM NAD27 LVGEOID (m) Conversion surface s (m) USGG2003

X Y height σ height σ height (m)

LINE 1: HIGHWAY 395

F124 350193 4158179 -24.721 0.028 0.038 0.027 -24.759

CROWLEY AZ 1 349651 4158000 -24.693 0.021 0.037 0.000 -24.73

P911 348423 4158055 -24.654 0.030 0.027 0.030 -24.681

P911 RESET 348418 4157745 -24.638 0.027 0.028 0.027 -24.666

E124 347595 4158659 -24.662 0.029 0.016 0.029 -24.678

C1433 346442 4158425 -24.619 0.030 0.007 0.030 -24.626

BMQ 346317 4158371 -24.613 0.029 0.006 0.029 -24.619

Q911 346128 4158619 -24.617 0.028 0.003 0.029 -24.62

D124 1

 344672 4159701 -24.634 0.013 -0.014 0.000 -24.62

U911 343683 4160674 -24.665 0.031 -0.020 0.031 -24.645

C124 342588 4161150 -24.656 0.029 -0.023 0.030 -24.633

6DOR 342545 4161184 -24.658 0.029 -0.024 0.030 -24.634

V911 1

 341581 4162068 -24.690 0.021 -0.027 0.000 -24.663

B124 340910 4163002 -24.727 0.029 -0.027 0.029 -24.7

7DOR 340789 4163160 -24.733 0.030 -0.027 0.030 -24.706

CONVICT 1

 340248 4164402 -24.805 0.014 -0.029 0.000 -24.776

8DOR 339180 4164856 -24.822 0.031 -0.044 0.031 -24.778

T911 RESET 338425 4165115 -24.833 0.030 -0.056 0.030 -24.777

9DOR 337742 4165406 -24.845 0.029 -0.067 0.029 -24.778

9DOR RESET 337742 4165406 -24.845 0.029 -0.067 0.029 -24.778

S911 RESET 336892 4165700 -24.854 0.028 -0.080 0.028 -24.774

A124 335522 4166104 -24.857 0.000 -0.097 0.019 -24.76

A124 RESET 1

 335576 4166125 -24.859 0.019 -0.097 0.000 -24.762

10DOR 334524 4166524 -24.857 0.021 -0.101 0.021 -24.756

R911 334603 4166456 -24.854 0.021 -0.100 0.021 -24.754

11DOR 333018 4167142 -24.848 0.021 -0.099 0.021 -24.749

MGB13 332965 4167110 -24.844 0.021 -0.098 0.021 -24.746

MGB14 332895 4167145 -24.843 0.020 -0.097 0.020 -24.746

MGB16 332852 4167201 -24.845 0.020 -0.097 0.020 -24.748

MGB17 332773 4167236 -24.844 0.021 -0.096 0.022 -24.748

11EGE 332730 4167270 -24.844 0.021 -0.096 0.022 -24.748

MGB18 332677 4167294 -24.844 0.022 -0.096 0.022 -24.748

MGB19 332651 4167294 -24.843 0.022 -0.096 0.022 -24.747

MGB20 332581 4167329 -24.843 0.022 -0.096 0.022 -24.747

MGB21 332528 4167330 -24.842 0.022 -0.096 0.022 -24.746

10EGE 332335 4167400 -24.841 0.022 -0.096 0.022 -24.745

9EGE 332145 4167582 -24.848 0.020 -0.096 0.020 -24.752

DBR1 332143 4167493 -24.841 0.020 -0.096 0.020 -24.745

DBR2 332117 4167527 -24.842 0.021 -0.096 0.021 -24.746

DBR3 332047 4167562 -24.842 0.021 -0.096 0.021 -24.746

DBR4 331995 4167585 -24.844 0.021 -0.095 0.021 -24.749

DBR5 331978 4167619 -24.845 0.020 -0.095 0.020 -24.75

8EGE 331952 4167686 -24.847 0.020 -0.095 0.020 -24.752

DBR6 331925 4167620 -24.844 0.020 -0.095 0.020 -24.749

DBR7 331873 4167687 -24.845 0.021 -0.095 0.021 -24.75

DBR8 331830 4167721 -24.846 0.021 -0.095 0.021 -24.751

DBR9 331759 4167745 -24.845 0.021 -0.095 0.021 -24.75

DBR10 331707 4167779 -24.842 0.019 -0.095 0.019 -24.747

Table 5. Geoid heights at leveling benchmarks for the Long Valley region (see fig. 1B for benchmark location).
26 Converting NAD83 GPS Heights Into NAVD88 Elevations With LVGEOID, Long Valley Volcanic Region, California

Table 5. Geoid heights at leveling benchmarks for the Long Valley region (see fig. 1B for benchmark location)—Continued.

BM

UTM NAD27 LVGEOID (m) Conversion surface s (m) USGG2003

X Y height σ height σ height (m)

DBR11 331637 4167814 -24.842 0.021 -0.095 0.022 -24.747

CASA AZ 331654 4167780 -24.841 0.019 -0.095 0.019 -24.746

7EGE 331419 4167907 -24.839 0.022 -0.094 0.022 -24.745

Z123 331200 4168034 -24.837 0.021 -0.093 0.021 -24.744

6EGE 331052 4168137 -24.838 0.020 -0.093 0.020 -24.745

5EGE 330862 4168296 -24.838 0.021 -0.092 0.021 -24.746

4EGE 330673 4168578 -24.843 0.021 -0.091 0.021 -24.752

3EGE 330527 4168791 -24.845 0.020 -0.089 0.020 -24.756

2EGE 330383 4169072 -24.850 0.018 -0.088 0.019 -24.762

1EGE 1

 330291 4169318 -24.854 0.021 -0.087 0.000 -24.767

W911 330131 4169699 -24.863 0.018 -0.089 0.019 -24.774

BM12 329714 4170873 -24.886 0.013 -0.099 0.013 -24.787

X911 329346 4171003 -24.882 0.014 -0.101 0.014 -24.781

12DOR 329559 4171897 -24.901 0.014 -0.108 0.014 -24.793

13DOR 1

 329092 4172773 -24.902 0.019 -0.117 0.000 -24.785

Y123 328821 4172901 -24.902 0.013 -0.121 0.013 -24.781

14DOR 328464 4173552 -24.905 0.014 -0.135 0.014 -24.77

Z1382 328371 4173742 -24.905 0.014 -0.138 0.014 -24.767

Z1382 RESET 328371 4173742 -24.905 0.014 -0.138 0.014 -24.767

D916 1

 328095 4174459 -24.903 0.018 -0.148 0.000 -24.755

EAL33 328124 4174602 -24.901 0.013 -0.146 0.013 -24.755

EAL15 1

 328038 4175137 -24.882 0.018 -0.133 0.000 -24.749

B13 327780 4175875 -24.854 0.014 -0.123 0.014 -24.731

69.97RT 327524 4176280 -24.830 0.014 -0.116 0.014 -24.714

Y911 327259 4176696 -24.797 0.014 -0.109 0.014 -24.688

Z911 326554 4177965 -24.730 0.017 -0.089 0.017 -24.641

15DOR 326407 4178102 -24.718 0.019 -0.086 0.019 -24.632

X123 1

 326127 4178629 -24.689 0.017 -0.079 0.000 -24.61

CRESTVIEW 326127 4178629 -24.689 0.000 -0.079 0.017 -24.61

A1383 325864 4179090 -24.662 0.023 -0.076 0.023 -24.586

CAL TRAN88 325591 4179962 -24.632 0.025 -0.072 0.025 -24.56

L916 325345 4179967 -24.621 0.026 -0.070 0.026 -24.551

L916 RESET 325345 4179967 -24.621 0.026 -0.070 0.026 -24.551

B1383 324754 4180812 -24.593 0.028 -0.069 0.028 -24.524

KUSE 324365 4181165 -24.570 0.028 -0.067 0.028 -24.503

A1391 323996 4181228 -24.555 0.030 -0.065 0.030 -24.49

B1391 323687 4181612 -24.539 0.029 -0.064 0.029 -24.475

BM2 323160 4182078 -24.517 0.030 -0.062 0.030 -24.455

T2SR 322099 4183201 -24.478 0.033 -0.059 0.033 -24.419

K916 322160 4183121 -24.481 0.032 -0.060 0.032 -24.421

16DOR 321303 4184250 -24.447 0.034 -0.057 0.034 -24.39

J916 320624 4185841 -24.429 0.033 -0.056 0.033 -24.373

H916 320553 4185809 -24.426 0.034 -0.055 0.034 -24.371

BM5 319470 4186632 -24.401 0.034 -0.053 0.034 -24.348

5 RESET 319470 4186632 -24.401 0.034 -0.053 0.034 -24.348

BM6 318614 4187762 -24.378 0.032 -0.052 0.032 -24.326

M916 317759 4188924 -24.360 0.029 -0.052 0.029 -24.308

BM7 1 317197 4190169 -24.355 0.013 -0.055 0.000 -24.3

N916 316757 4191378 -24.356 0.030 -0.064 0.030 -24.292
Tables 1–5 27

Table 5. Geoid heights at leveling benchmarks for the Long Valley region (see fig. 1B for benchmark location)—Continued.

BM

UTM NAD27 LVGEOID (m) Conversion surface s (m) USGG2003

X Y height σ height σ height (m)

W123 316514 4192316 -24.360 0.030 -0.071 0.030 -24.289

W123 RESET 316421 4192495 -24.359 0.030 -0.073 0.030 -24.286

R916 316393 4193584 -24.376 0.028 -0.082 0.028 -24.294

JUCTION 1 316233 4195097 -24.392 0.018 -0.093 0.000 -24.299

V123 316045 4195313 -24.385 0.026 -0.093 0.026 -24.292

DIABLO 316060 4196023 -24.394 0.026 -0.095 0.026 -24.299

DIABLO RESET 316060 4196023 -24.394 0.026 -0.095 0.026 -24.299

Q916 315869 4197293 -24.397 0.028 -0.095 0.028 -24.302

P916 315774 4198560 -24.407 0.028 -0.095 0.028 -24.312

U123 315350 4200413 -24.407 0.024 -0.094 0.024 -24.313

C916 1

 315132 4201661 -24.414 0.018 -0.094 0.000 -24.32

LINE 2: HIGHWAY 203

CASA AZ 331654 4167780 -24.841 0.019 -0.095 0.019 -24.746

DBR11 331637 4167814 -24.842 0.021 -0.095 0.022 -24.747

DBR12 331584 4167782 -24.839 0.019 -0.095 0.019 -24.744

DBR13 331512 4167750 -24.836 0.021 -0.095 0.021 -24.741

DBR14 331485 4167728 -24.835 0.021 -0.095 0.021 -24.74

DBR15 331432 4167696 -24.832 0.021 -0.095 0.021 -24.737

DBR17 331360 4167631 -24.828 0.021 -0.095 0.021 -24.733

DBR18 331289 4167599 -24.825 0.022 -0.095 0.022 -24.73

DBR19 331209 4167601 -24.823 0.022 -0.095 0.022 -24.728

DBR20 331138 4167580 -24.820 0.022 -0.095 0.022 -24.725

DBR21 331093 4167548 -24.818 0.020 -0.095 0.020 -24.723

33EGE 330819 4167520 -24.812 0.021 -0.095 0.021 -24.717

1LRM 330543 4167404 -24.803 0.021 -0.096 0.021 -24.707

34EGE 330500 4167438 -24.803 0.022 -0.096 0.022 -24.707

1JCM 330084 4167380 -24.795 0.021 -0.097 0.022 -24.698

2LRM 329712 4167332 -24.789 0.021 -0.099 0.021 -24.69

35EGE 329518 4167336 -24.787 0.022 -0.100 0.022 -24.687

36EGE 329271 4167341 -24.784 0.019 -0.101 0.019 -24.683

37EGE 328955 4167436 -24.784 0.020 -0.103 0.020 -24.681

38EGE 328807 4167528 -24.786 0.019 -0.104 0.019 -24.682

2JCM 1

 328809 4167628 -24.790 0.019 -0.104 0.000 -24.686

39EGE 328371 4167792 -24.790 0.018 -0.104 0.018 -24.686

40EGE 328084 4168009 -24.791 0.021 -0.104 0.021 -24.687

3LRM 327689 4168140 -24.788 0.023 -0.104 0.023 -24.684

STA907 327645 4168141 -24.788 0.023 -0.104 0.023 -24.684

41EGE 327374 4168235 -24.786 0.020 -0.104 0.020 -24.682

3JCM 327207 4168305 -24.785 0.021 -0.103 0.021 -24.682

K1383 1

 326150 4168416 -24.763 0.026 -0.098 0.000 -24.665

4JCM 325038 4168839 -24.714 0.024 -0.062 0.024 -24.652

J1383 325154 4168470 -24.714 0.026 -0.069 0.026 -24.645

H1383 324725 4169034 -24.702 0.027 -0.051 0.027 -24.651

5JCM 1

 324334 4169320 -24.690 0.042 -0.038 0.000 -24.652

G1383 324081 4169048 -24.681 0.028 -0.038 0.028 -24.643

F1383 323633 4168725 -24.669 0.030 -0.037 0.030 -24.632

6JCM 323538 4168849 -24.669 0.029 -0.036 0.029 -24.633

E1383 322971 4168761 -24.659 0.031 -0.034 0.031 -24.625
28 Converting NAD83 GPS Heights Into NAVD88 Elevations With LVGEOID, Long Valley Volcanic Region, California

Table 5. Geoid heights at leveling benchmarks for the Long Valley region (see fig. 1B for benchmark location)—Continued.

BM

UTM NAD27 LVGEOID (m) Conversion surface s (m) USGG2003

X Y height σ height σ height (m)

7JCM 322603 4168469 -24.658 0.032 -0.034 0.032 -24.624

8JCM 321646 4168701 -24.642 0.033 -0.032 0.033 -24.61

JEE1 321481 4168826 -24.637 0.033 -0.032 0.033 -24.605

JEE3 321307 4168952 -24.629 0.032 -0.032 0.032 -24.597

JEE6 321142 4169078 -24.623 0.032 -0.032 0.032 -24.591

JEE9 320979 4169270 -24.615 0.032 -0.032 0.032 -24.583

JEE12 320871 4169184 -24.616 0.031 -0.032 0.031 -24.584

JEE15 320772 4169119 -24.616 0.031 -0.032 0.031 -24.584

JEE17 320675 4169088 -24.616 0.032 -0.032 0.032 -24.584

JEE19 320576 4169035 -24.616 0.032 -0.032 0.032 -24.584

JEE20 320479 4169003 -24.616 0.032 -0.032 0.032 -24.584

JEE22 320354 4168973 -24.615 0.032 -0.032 0.032 -24.583

PM14 320472 4168980 -24.616 0.032 -0.032 0.032 -24.584

9JCM 320230 4168920 -24.616 0.030 -0.032 0.030 -24.584

42EGE 319083 4168945 -24.605 0.032 -0.032 0.032 -24.573

D1383 318568 4169234 -24.583 0.031 -0.032 0.031 -24.551

20JD 318551 4169234 -24.582 0.031 -0.032 0.031 -24.55

RET 1

 318310 4169517 -24.560 0.014 -0.033 0.000 -24.527

LINE 3: LOOKOUT MTN-CASHBAUGH RANCH-WHITMORE HOT SPRINGS-CONVICT CREEK

8DOR 339180 4164856 -24.822 0.031 -0.044 0.031 -24.778

T911 RESET 338425 4165115 -24.833 0.030 -0.056 0.030 -24.777

9DOR RESET 337742 4165406 -24.845 0.029 -0.067 0.029 -24.778

1JD 340232 4166312 -24.934 0.028 -0.057 0.028 -24.877

48DOR 340225 4166867 -24.965 0.027 -0.065 0.026 -24.9

47DOR 340417 4168129 -25.026 0.020 -0.082 0.020 -24.944

46DOR 340781 4169143 -25.069 0.018 -0.095 0.018 -24.974

45DOR 340212 4170297 -25.093 0.014 -0.109 0.014 -24.984

2JD 340272 4170662 -25.102 0.013 -0.113 0.013 -24.989

29JCM 1

 340792 4171085 -25.121 0.019 -0.120 0.000 -25.001

44DOR 1

 340748 4171086 -25.121 0.017 -0.120 0.000 -25.001

43DOR 340344 4172115 -25.128 0.013 -0.126 0.013 -25.002

42DOR 340072 4173108 -25.127 0.014 -0.127 0.014 -25

41DOR 340380 4173957 -25.126 0.015 -0.127 0.015 -24.999

40DOR 340648 4175062 -25.107 0.017 -0.120 0.017 -24.987

39DOR 340138 4176492 -25.059 0.018 -0.112 0.018 -24.947

38DOR 339911 4177551 -25.015 0.021 -0.108 0.021 -24.907

26DOR 339094 4178144 -24.979 0.023 -0.106 0.023 -24.873

25DOR 337403 4178211 -24.957 0.020 -0.106 0.020 -24.851

24DOR 336407 4178663 -24.942 0.021 -0.127 0.021 -24.815

23DOR 334991 4178847 -24.891 0.023 -0.095 0.023 -24.796

G916 333534 4179120 -24.858 0.021 -0.094 0.021 -24.764

F916 331752 4179501 -24.813 0.020 -0.095 0.020 -24.718

NUSE 331505 4179506 -24.808 0.021 -0.095 0.020 -24.713

E916 329965 4179626 -24.771 0.020 -0.091 0.020 -24.68

MUSE 328750 4178852 -24.781 0.019 -0.095 0.020 -24.686

LUSE 327572 4177733 -24.796 0.016 -0.102 0.016 -24.694

69.97RT 327524 4176280 -24.830 0.014 -0.116 0.014 -24.714

B13 327780 4175875 -24.854 0.014 -0.123 0.014 -24.731
Tables 1–5 29

Table 5. Geoid heights at leveling benchmarks for the Long Valley region (see fig. 1B for benchmark location)—Continued.

BM

UTM NAD27 LVGEOID (m) Conversion surface s (m) USGG2003

X Y height σ height σ height (m)

LINE 4: CASHBAUGH RANCH-LITTLE ANTELOPE VALLEY-CASA

29JCM 1

 340792 4171085 -25.121 0.019 -0.120 0.000 -25.001

44DOR 1

 340748 4171086 -25.121 0.017 -0.120 0.000 -25.001

43DOR 340344 4172115 -25.128 0.013 -0.126 0.013 -25.002

28JCM 339570 4171297 -25.102 0.014 -0.117 0.014 -24.985

28JCM RESET 339570 4171297 -25.102 0.014 -0.117 0.014 -24.985

27JCM 338774 4171646 -25.086 0.014 -0.115 0.014 -24.971

26JCM 1

 337627 4172101 -25.066 0.020 -0.112 0.000 -24.954

25JCM 1

 336091 4172531 -25.034 0.023 -0.109 0.000 -24.925

18JCM 334933 4171966 -25.012 0.013 -0.111 0.013 -24.901

18JCM RESET 334933 4171966 -25.012 0.013 -0.111 0.013 -24.901

KWH16 334854 4171967 -25.010 0.013 -0.111 0.013 -24.899

KWH15 334809 4171946 -25.010 0.013 -0.111 0.013 -24.899

KWH14 334782 4171880 -25.009 0.013 -0.111 0.013 -24.898

KWH13 334754 4171825 -25.008 0.013 -0.111 0.013 -24.897

KWH12 334727 4171792 -25.006 0.013 -0.111 0.013 -24.895

KWH11 334726 4171759 -25.005 0.013 -0.111 0.013 -24.894

KWH10 334709 4171759 -25.005 0.013 -0.111 0.013 -24.894

KWH9 334629 4171728 -25.004 0.013 -0.112 0.013 -24.892

KWH8 334558 4171729 -25.003 0.013 -0.112 0.013 -24.891

KWH7 334504 4171697 -25.002 0.000 -0.112 0.000 -24.89

KWH6 1

 334460 4171676 -25.001 0.020 -0.112 0.000 -24.889

KWH5 334407 4171677 -25.000 0.000 -0.112 0.000 -24.888

KWH4 334381 4171699 -25.000 0.000 -0.112 0.000 -24.888

17JCM 333626 4171903 -24.996 0.013 -0.116 0.013 -24.88

27EGE 333701 4171691 -24.994 0.012 -0.115 0.012 -24.879

26EGE 333615 4171348 -24.989 0.013 -0.115 0.013 -24.874

25EGE 1

 333592 4171071 -24.988 0.022 -0.115 0.000 -24.873

24EGE 333265 4171045 -24.982 0.014 -0.114 0.014 -24.868

21JCM 332976 4171150 -24.980 0.012 -0.113 0.012 -24.867

23EGE 332687 4171245 -24.976 0.013 -0.112 0.013 -24.864

22EGE 332465 4171216 -24.970 0.014 -0.110 0.014 -24.86

21EGE 332465 4171216 -24.970 0.014 -0.110 0.014 -24.86

22JCM 332215 4171066 -24.961 0.013 -0.109 0.014 -24.852

20EGE 332114 4170857 -24.953 0.013 -0.107 0.014 -24.846

19EGE 332055 4170581 -24.944 0.014 -0.105 0.014 -24.839

18EGE 1

 331855 4170274 -24.928 0.029 -0.100 0.000 -24.828

17EGE 331824 4170064 -24.922 0.013 -0.100 0.013 -24.822

23JCM 331824 4170064 -24.922 0.013 -0.100 0.013 -24.822

16EGE 331550 4169603 -24.898 0.017 -0.096 0.017 -24.802

15EGE 331421 4169328 -24.886 0.018 -0.094 0.019 -24.792

14EGE 331126 4169146 -24.871 0.018 -0.091 0.018 -24.78

24JCM 331096 4168969 -24.865 0.019 -0.091 0.019 -24.774

13EGE 330967 4168716 -24.854 0.019 -0.091 0.019 -24.763

12EGE 330752 4168976 -24.855 0.019 -0.089 0.019 -24.766

3EGE 330527 4168791 -24.845 0.020 -0.089 0.020 -24.756
30 Converting NAD83 GPS Heights Into NAVD88 Elevations With LVGEOID, Long Valley Volcanic Region, California

Table 5. Geoid heights at leveling benchmarks for the Long Valley region (see fig. 1B for benchmark location)—Continued.

BM

UTM NAD27 LVGEOID (m) Conversion surface s (m) USGG2003

X Y height σ height σ height (m)

LINE 5: SMOKEY BEAR FLAT-RESURGENT DOME-LITTLE ANTELOPE VALLEY

17JCM 333626 4171903 -24.996 0.013 -0.116 0.013 -24.88

16PDI 333724 4171935 -24.996 0.012 -0.115 0.012 -24.881

15PDI 333804 4171988 -24.997 0.012 -0.114 0.012 -24.883

14PDI 333977 4172240 -25.002 0.013 -0.115 0.013 -24.887

4PDI 333886 4172542 -25.004 0.012 -0.116 0.012 -24.888

12PDI 333792 4172699 -25.005 0.013 -0.117 0.013 -24.888

31EGE 333797 4172954 -25.008 0.012 -0.118 0.012 -24.89

11PDI 333873 4173197 -25.013 0.013 -0.119 0.013 -24.894

10PDI 333753 4173355 -25.013 0.014 -0.120 0.014 -24.893

16JCM 333520 4173659 -25.014 0.014 -0.122 0.014 -24.892

9PDI 333400 4173817 -25.014 0.014 -0.123 0.014 -24.891

8PDI 333160 4174133 -25.006 0.015 -0.115 0.015 -24.891

32EGE 332914 4174204 -25.003 0.015 -0.116 0.015 -24.887

7PDI 332748 4174263 -25.001 0.015 -0.116 0.015 -24.885

15JCM 332779 4174485 -25.000 0.014 -0.116 0.014 -24.884

6PDI 332678 4174731 -24.997 0.013 -0.117 0.013 -24.88

5PDI 332585 4174921 -24.994 0.014 -0.118 0.014 -24.876

3PDI 1984 332567 4174922 -24.994 0.014 -0.118 0.014 -24.876

2PDI 1984 332420 4175047 -24.989 0.016 -0.118 0.016 -24.871

1PDI 1984 332231 4175295 -24.982 0.014 -0.119 0.014 -24.863

2PDI 1983 332110 4175419 -24.982 0.015 -0.124 0.015 -24.858

1PDI 1983 332088 4175631 -24.977 0.016 -0.124 0.016 -24.853

14JCM 332145 4175852 -24.962 0.016 -0.112 0.016 -24.85

13JCM 331088 4175907 -24.937 0.015 -0.115 0.015 -24.822

12JCM 330044 4175306 -24.931 0.014 -0.126 0.014 -24.805

L1383 330183 4174782 -24.943 0.013 -0.127 0.014 -24.816

11JCM 329670 4174726 -24.930 0.014 -0.130 0.014 -24.8

10JCM 329256 4173880 -24.922 0.013 -0.131 0.013 -24.791

13DOR 329092 4172773 -24.902 0.000 -0.117 0.000 -24.785

LINE 6: LAKE CROWLEY TIE A

43DOR 340344 4172115 -25.128 0.013 -0.126 0.013 -25.002

44DOR 340748 4171086 -25.121 0.000 -0.120 0.000 -25.001

29JCM 340792 4171085 -25.121 0.000 -0.120 0.000 -25.001

49DOR 341432 4172249 -25.154 0.013 -0.140 0.013 -25.014

T3S R29E 1 342238 4172445 -25.166 0.021 -0.145 0.000 -25.021

3JD 342363 4172531 -25.164 0.013 -0.143 0.013 -25.021

50DOR 343685 4172450 -25.136 0.015 -0.115 0.015 -25.021

4JD 1 344644 4173720 -25.090 0.020 -0.089 0.000 -25.001

51DOR 345725 4172590 -25.087 0.024 -0.083 0.024 -25.004

52DOR 346806 4171404 -25.072 0.029 -0.074 0.029 -24.998

53DOR 347664 4170090 -25.052 0.031 -0.066 0.031 -24.986

54DOR 348132 4169160 -25.021 0.034 -0.048 0.034 -24.973

6JD 347895 4168243 -25.012 0.035 -0.045 0.035 -24.967

55DOR 348436 4166934 -24.971 0.037 -0.033 0.038 -24.938

56DOR 348436 4166934 -24.971 0.037 -0.033 0.038 -24.938

LC4B 348191 4167061 -24.978 0.036 -0.035 0.037 -24.943

LC4A 347697 4166582 -24.971 0.036 -0.035 0.036 -24.936
Tables 1–5 31

Table 5. Geoid heights at leveling benchmarks for the Long Valley region (see fig. 1B for benchmark location)—Continued.

BM

UTM NAD27 LVGEOID (m) Conversion surface s (m) USGG2003

X Y height σ height σ height (m)

TBM LC4 347495 4166208 -24.963 0.035 -0.034 0.035 -24.929

LINE 7: CONVICT LAKE SPUR

9DOR RESET 337742 4165406 -24.845 0.029 -0.067 0.029 -24.778

30JCM 337210 4164373 -24.770 0.031 -0.064 0.031 -24.706

31JCM 336668 4163307 -24.678 0.031 -0.064 0.032 -24.614

32JCM 336621 4162253 -24.609 0.033 -0.063 0.033 -24.546

33JCM 336370 4161614 -24.555 0.034 -0.062 0.034 -24.493

LINE 8: DEADMAN SPUR

EAL15 328038 4175137 -24.882 0.000 -0.133 0.000 -24.749

EAL3 328038 4175137 -24.882 0.000 -0.133 0.000 -24.749

34JCM 327392 4175028 -24.855 0.014 -0.129 0.014 -24.726

EAL1 327392 4175028 -24.855 0.014 -0.129 0.014 -24.726

35JCM 326049 4174923 -24.792 0.013 -0.107 0.013 -24.685

36JCM 325473 4175624 -24.751 0.016 -0.095 0.016 -24.656

37JCM 324695 4175940 -24.709 0.022 -0.085 0.022 -24.624

38JCM 323759 4176704 -24.642 0.025 -0.073 0.025 -24.569

39JCM 322233 4176270 -24.583 0.030 -0.061 0.030 -24.522

40JCM 321591 4176351 -24.560 0.032 -0.057 0.032 -24.503

LINE 9: SHERWIN CREEK-YMCA CAMP SPUR

MGB13 332965 4167110 -24.844 0.021 -0.098 0.021 -24.746

11DOR 333018 4167142 -24.848 0.021 -0.099 0.021 -24.749

MGB10 333040 4166920 -24.837 0.023 -0.098 0.023 -24.739

MGB9 333286 4166859 -24.840 0.023 -0.098 0.024 -24.742

MGB8 333036 4166709 -24.827 0.022 -0.098 0.022 -24.729

MGB7 332983 4166677 -24.826 0.022 -0.099 0.022 -24.727

MGB6 332955 4166611 -24.822 0.022 -0.099 0.022 -24.723

LC1 332937 4166611 -24.822 0.022 -0.099 0.022 -24.723

MGB5 332937 4166589 -24.820 0.022 -0.099 0.021 -24.721

MGB4 332936 4166556 -24.819 0.022 -0.099 0.021 -24.72

MGB3 332909 4166523 -24.817 0.022 -0.099 0.022 -24.718

MGB2 332855 4166491 -24.814 0.022 -0.099 0.022 -24.715

MGB1 332728 4166316 -24.803 0.023 -0.099 0.023 -24.704

28EGE 332610 4166129 -24.792 0.024 -0.099 0.024 -24.693

LC2 332480 4165821 -24.774 0.024 -0.099 0.024 -24.675

29EGE 332256 4165670 -24.754 0.023 -0.096 0.023 -24.658

30EGE 332007 4165587 -24.746 0.024 -0.096 0.024 -24.65

LC3 331812 4165557 -24.741 0.025 -0.096 0.025 -24.645

LAKE CROWLEY TIE B

1JD 340232 4166312 -24.934 0.028 -0.057 0.028 -24.877

48DOR 340225 4166867 -24.965 0.027 -0.065 0.026 -24.9

47DOR 340417 4168129 -25.026 0.020 -0.082 0.020 -24.944

46DOR 340781 4169143 -25.069 0.018 -0.095 0.018 -24.974

LC3E 342195 4168772 -25.071 0.022 -0.087 0.022 -24.984

LC3D 342979 4168734 -25.073 0.023 -0.083 0.023 -24.99

LC3C 344308 4169009 -25.079 0.023 -0.079 0.022 -25

LC3B 345492 4169542 -25.082 0.027 -0.078 0.027 -25.004

LC3A 345597 4168530 -25.055 0.029 -0.065 0.029 -24.99

TBM LC3 345623 4168529 -25.054 0.029 -0.064 0.029 -24.99
32 Converting NAD83 GPS Heights Into NAVD88 Elevations With LVGEOID, Long Valley Volcanic Region, California

Table 5. Geoid heights at leveling benchmarks for the Long Valley region (see fig. 1B for benchmark location)—Continued.

BM

UTM NAD27 LVGEOID (m) Conversion surface s (m) USGG2003

X Y height σ height σ height (m)

LAKE CROWLEY TIE C

1JD 340232 4166312 -24.934 0.028 -0.057 0.028 -24.877

LC2D 341542 4166475 -24.960 0.030 -0.054 0.030 -24.906

LC2C 342902 4166050 -24.956 0.031 -0.048 0.031 -24.908

LC2B 344414 4165710 -24.947 0.033 -0.036 0.033 -24.911

LC2A 345056 4164655 -24.903 0.033 -0.026 0.033 -24.877

TBM LC2 345054 4164533 -24.898 0.032 -0.026 0.032 -24.872

MARY LAKE ROAD

J1383 325154 4168470 -24.714 0.026 -0.069 0.026 -24.645

CVO89-311 324483 4168018 -24.682 0.027 -0.056 0.027 -24.626

VISTA89 323772 4166990 -24.652 0.032 -0.052 0.032 -24.6

CVO89-310 323569 4166595 -24.646 0.032 -0.051 0.032 -24.595

CVO89-309 323181 4165770 -24.636 0.033 -0.050 0.034 -24.586

CVO89-308 323330 4164868 -24.621 0.035 -0.054 0.035 -24.567

CVO89-307 323397 4164289 -24.611 0.035 -0.055 0.036 -24.556

CVO89-306 323463 4164066 -24.607 0.035 -0.056 0.035 -24.551

CVO89-305 323529 4163854 -24.597 0.038 -0.056 0.038 -24.541

CVO89-304 323332 4163758 -24.596 0.038 -0.055 0.038 -24.541

CVO89-303 323171 4164072 -24.608 0.038 -0.053 0.038 -24.555

CVO89-302 322998 4164231 -24.613 0.038 -0.052 0.038 -24.561

CVO89-301 322516 4164397 -24.624 0.038 -0.048 0.038 -24.576

CVO89-300 321780 4164657 -24.638 0.037 -0.043 0.038 -24.595

1

 Experimental sites (see also table 2).
Battaglia and Others—Converting NAD83 GPS Heights Into NAVD88 Elevations with LVGEOID, a Hybrid Geoid Height Model for the 

Long Valley Volcanic Region, California—Scientific Investigations Report 2007–5255