Latitude-longitude grid, UTM zone boundary, and state plane coordinate system zone boundary

80¡81¡82¡83¡84¡

85¡

42¡

41¡

40¡

39¡

38¡

10 20 30 miles

10 20 30

40 kilometers

LATITUDE-LONGITUDE GRID, UTM ZONE BOUNDARY, AND

STATE PLANE COORDINATE SYSTEM ZONE BOUNDARY

WILLIAMS FULTON LUCAS

OTTAWA

WOOD

HENRY

DEFIANCE

HARDIN

HANCOCK

AUGLAIZE

ALLEN

PUTNAM

MERCER

VAN WERT

PAULDING

HOLMES

ERIE

SANDUSKY

SENECA

HURON

LORAIN

MEDINA

WAYNE

ASHLANDRICHLANDCRAWFORD

MORROW

WYANDOT

MARION

CARROLL

STARK

COLUMBIANA

MAHONING

TRUMBULL

PORTAGE

SUMMIT

GEAUGA

ASHTABULA

LAKE

CUYAHOGA

UNION

DELAWARE

KNOX

COSHOCTON

TUSCARAWAS

HARRISON

JEFFERSON

FAYETTE

PICKAWAY

FRANKLIN

MADISON

CLARK

MONTGOMERY

PREBLE

CHAMPAIGN

MIAMI

LOGAN

SHELBY

DARKE

BROWN

HIGHLAND

GREENE

CLINTON

WARREN

CLERMONT

HAMILTON

BUTLER

BELMONT

GUERNSEY

NOBLE

MONROE

MUSKINGUM

MORGAN

WASHINGTON

LICKING

PERRY

FAIRFIELD

HOCKING

ATHENS

MEIGS

VINTON

JACKSON

GALLIA

LAWRENCE

ROSS

PIKE

ADAMS

SCIOTO

Recommended citation: Ohio Division of Geological Survey, [n.d.], Latitude-longitude grid, UTM zone boundary, and state plane coordinate

system zone boundary: Ohio Department of Natural Resources, Division of Geological Survey, page size with text, 2 p., scale 1:2,550,000.

STATE PLANE NORTH

STATE PLANE SOUTH

UTM

ZONE 16

UTM

ZONE 17

STATE OF OHIO ¥ DEPARTMENT OF NATURAL RESOURCES ¥ DIVISION OF GEOLOGICAL SURVEY

COMMON COORDINATE SYSTEMS USED IN OHIO

Use of a coordinate system is necessary to define a position on our spherical Earth.

The accompanying map illustrates the coverage and boundaries of three of the most

commonly used systems in Ohio. The best known and most commonly used system of

reference coordinates is latitude and longitude. Lines of longitude (meridians) are

a series of 360 circles around the Earth that pass through the North and South Poles.

Lines of latitude (parallels) run east-west parallel to the Equator; there are 90 lines of

latitude in each hemisphere, north and south. Latitude and longitude are measured

in degrees (˚), minutes ('), and seconds ("). Ohio lies between 80˚ and 85˚ west longi-

tude and between 38˚ and 42˚ north latitude. To use this geographic coordinate sys-

tem, measurements and computations must be performed using angular units and

relationships because it is a network of gridlines placed around a sphere.

Rectangular coordinate systems use different methods to represent (project) Earth’s

three-dimensional spherical shape on a two-dimensional reference grid. Rectangular

coordinate systems involve less complicated calculations of distance, area, and posi-

tion. However, the projection methods used cause distortions of the Earth’s surface by

stretching or compressing shape, area, or scale. The two most commonly used projec-

tion systems in this area are the Lambert and Transverse Mercator, both of which have

varying scale but retain the proper shape of the mapped surface.

The state plane coordinate system was introduced in the 1930’s to allow the

entire conterminous United States to be mapped on a set of flat surfaces with very

little local distortion. The size and orientation of each state determines how many

zones are used and which projection provides the least distortion. Two Lambert pro-

jection zones cover Ohio: a north zone and a south zone. Measurements are in feet

and, within each zone, are all positive. The boundary between the two zones follows

county lines as depicted on the accompanying map.

The Universal Tranverse Mercator (UTM) coordinate system was developed by

the U.S. Department of Defense for global military operations. The UTM system con-

sists of 60 north-south zones arranged around the globe. Each zone is 6° of longitude

wide. The zones are numbered from west to east beginning at the 180th meridian, and

within each zone all coordinates are positive values. UTM measurements commonly

are in meters, although these can be converted to feet. Ohio lies within a portion of

zones 16 and 17 as depicted on the accompanying map.

Most maps being produced by the Ohio Division of Geological Survey today are pre-

pared electronically. The most common coordinate system used by the Survey in its

digital mapping systems is the state plane coordinate system. For statewide maps,

the south zone of the state plane system is extended over the entire state. When using

the Survey’s digital map products, it is important to obtain the accompanying metadata

files that explain the coordinate system, scale, and projection used in creating the

map. Most digital mapping systems provide easy methods for converting between dif-

ferent projections and coordinate systems.