Geologic Map of Io, SIM 3168

Primary Authors

David A. Williams

Originators

Laszlo P. Keszthelyi, David A. Crown, Jessica A. Yff, Windy L. Jaeger, Paul M. Schenk, Paul E. Geissler, Tammy L. Becker

Publisher

USGS Astrogeology Science Center

Publication Date

2012-03-13

Abstract

Io, discovered by Galileo Galilei on January 7-13, 1610, is the innermost of the four Galilean satellites of the planet Jupiter. It is the most volcanically active object in the Solar System, as recognized by observations from six U.S. National Aeronautics and Space Administration (NASA) spacecraft: Voyager 1 (March 1979), Voyager 2 (July 1979), Hubble Space Telescope (1990-Present), Galileo (1996-2001), Cassini (December 2000), and New Horizons (February 2007). The lack of impact craters on Io in any spacecraft images at any resolution attests to the high resurfacing rate (~1 cm/yr) and the dominant role of active volcanism in shaping its surface (Johnson and others, 1979). High-temperature hot spots detected by the Galileo Solid-State Imager (SSI), Near-Infrared Mapping Spectrometer (NIMS) and Photopolarimeter-Radiometer (PPR) usually correlate with darkest materials on the surface, suggestive of active volcanism. The Voyager flybys obtained complete coverage of Io's subjovian hemisphere at ~500 m/pixel to 2 km/pixel and most of the rest of the satellite at 5-20 km/pixel. Repeated Galileo flybys obtained complementary coverage of Io's antijovian hemisphere at 5 m/pixel to 1.4 km/pixel. Thus, the Voyager and Galileo data sets were merged to enable the characterization of the whole surface of the satellite at a consistent resolution.The U.S. Geological Survey (USGS) produced a set of four global mosaics of Io in visible wavelengths at a spatial resolution of 1 km/pixel, released in February 2006, which we have used as base maps for this new global geologic map. Suggested Citation: Williams, D.A., Keszthelyi, L.P., Crown, D.A., Yff, J.A., Jaeger, W.L., Schenk, P.M., Geissler, P.E., and Becker, T.L., 2011, Geologic map of Io: U.S. Geological Survey Scientific Investigations Map 3168, scale 1:15,000,000, 25 p., available at http://pubs.usgs.gov/sim/3168 References: Bagenal, F., W. McKinnon, and T. Dowling, 2004, Jupiter: planet, satellites and magnetosphere: New York, Cambridge University Press, 719 p. Davies, A.G., 2007, Volcanism on Io: London, Cambridge University Press, 355 p. Lopes, R.M.C., and Spencer, J.R., 2007, Io After Galileo: Chichester, UK, Springer/Praxis Publishers, 342 p. Becker, T., and Geissler, P., 2005, Galileo global color mosaics of Io:, Houston, Lunar and Planetary Institute, Lunar and Planetary Science XXXVI, Abstract #1862 (CD-ROM).

Purpose

Much has been learned about Io's volcanism, tectonics, degradation, and interior since the Voyager flybys, primarily during and following the Galileo Mission at Jupiter (December 1995-September 2003). Our mapping incorporates this new understanding to assist in map unit definition and provide a global synthesis of Io's geology.

Contact and Distribution

Format

Geologic Map, Nomenclature

Access Constraints

public domain

Access Scope

MRCTR, PGM, RPIF

Use Constraints

Please cite authors

Series Id

3168

Edition

1

Supplemental Information

http://pubs.usgs.gov/sim/3168/

Native Data Set Environment

ESRI Arcinfo

Astrogeology Theme

Geographic Information System (GIS), Geology, Volcanism

Mission Names

Galileo, Voyager

Instrument Names

Voyager 1, Voyager 2

Online Package Link

https://astrogeology.usgs.gov/search/map/geologic_map_of_io_sim_3168

External File Size

281070604

Online File Link

http://astropedia.astrogeology.usgs.gov/download/Io/Geology/Io_SIM3168_Database.zip

Contact Address

2255 N. Gemini Drive

Contact City

Flagstaff

Contact State

AZ

Contact Postal Code

86001

Contact Email

astroweb@usgs.gov

Data Status and Quality

Time Period of Content (start)

2006-05-01

Time Period of Content (stop)

2011-05-01

Currentness Reference

Ground condition

Progress

Complete

Update Frequency

None planned

Logical Consistency

These data are believed to be logically consistent. Line geometry is topologically clean.

Completeness Report

Completed at the given scale for publication by USGS.

Process Description

Geologic mapping of Io has focused on specific types of geologic material units and structural features, as first recognized by Schaber (1980, 1982). The reasons for this are (1) the quantity of concurrent volcanic activity on Io and (2) the variable quality of the global spacecraft data. These constraints mean that it is not practical to separate map units based on both age and lithology. The mapping strategy developed for the global map was initially tested through mapping of the polar regions with ArcGIS software (by Esri) and then applied to the equatorial region.

Lineage

Process Date

2011-05-01

Source Title

Galileo global color mosaics of Io

Source Online Linkage

http://astrogeology.usgs.gov/maps/io-voyager-galileo-global-mosaics

Attribute Accuracy Report

Accurate to Control Net

Horizontal Positional Accuracy Report

Accurate to Control Net

Geospatial Information

Target

Io

System

Jupiter

Minimum Latitude

-90

Maximum Latitude

90

Minimum Longitude

0

Maximum Longitude

360

Direct Spatial Reference Method

Vector

Object Type

Grid Cell

Quad Name

Radius A

1821460

Radius C

1821460

Map Projection Name

Simple Cylindrical

Latitude Type

Planetocentric

Longitude Direction

Positive West

Longitude Domain

0 to 360