Three-Dimensional Earth Science

Models

Scientists have always struggled to find an

appropriate technology that could

represent three-dimensional (3-D) data,

facilitate dynamic analysis, and encourage

on-the-fly interactivity. In the recent past,

scientific visualization has increased the

scientist's ability to visualize information,

but it has not provided the interactive

environment necessary for rapidly

changing the model or for viewing the

model in ways not predetermined by the

visualization specialist. 

Virtual Reality Modeling Language

(VRML 2.0) is a new environment for

visualizing 3-D information spaces and is

accessible through the Internet with

current browser technologies. Researchers

from the U.S. Geological Survey (USGS)

are using VRML as a scientific visualization tool to help convey complex scientific

concepts to various audiences. Kevin W.

Laurent, computer scientist, and Maura J.

Hogan, technical information specialist,

have created a collection of VRML

models available through the Internet at

Virtual Earth Science (virtual.er.usgs.gov).

Recent Earthquakes

One of the first VRML applications

implemented through the USGS Web is a

model called Recent Earthquakes 

(virtual.er.usgs.gov/recent.html), which is

created in real time and is based on the

most recent significant earthquakes from

around the world as reported by the

USGS’s National Earthquake Information

Center (neic.usgs.gov). Although this

application uses a small subset of

earthquakes, the resulting model still

conveys the concept that earthquakes tend

to occur along plate boundaries. This

visualization effectively illustrates the

dynamics of plate tectonics. 

When demonstrated for school tours and

public exhibits, this model was especially

well received. Students, parents, and

teachers commented on the model’s use of

real-time data, its accessibility through the

Internet, and its capability of being

examined from any perspective. “The

students I’ve worked with are really drawn

to the VRML models,” said Maura Hogan.

“The combination of the computer, the

Internet, and highly illustrative graphics

captures their imagination and their

interest.”

Mount St. Helens

Another application, Mount St. Helens:

Before and After (virtual.er.usgs.

gov/mshCompare.html), uses USGS

digital elevation models (DEM) to create

virtual terrains of the volcano before and

after its 1980 eruption. The result is a

model that helps convey the immense

volume of the mountain that was ejected

in the eruption.

Earthquakes Inside Volcanoes

Working with Michael P. Ryan, a USGS

volcanologist, Kevin Laurent and Maura

Hogan developed several models that use

3-D earthquake locations to hint at a

volcano’s internal “plumbing system.”

This plumbing system shows the movement of magma inside a volcano. One of

the most recent models is of the island of

Hawaii (virtual.er.usgs.gov/Hawaii.html)

and focuses on the area containing Mauna

Loa, Kilauea, and Loihi. This model

represents the location of more than

27,000 earthquake events recorded over a

period of almost 30 years (1969-1997) and

allows the user to animate the series of

events to show the passage of time. 

“Using VRML allows us to render

complex data sets in an environment

where the scientist can examine the data in

ways previously impossible,” explains

Kevin Laurent. “The scientist’s ability to

move from visualization to theory

formulation is compelling.”

VRML is a valuable technology that can

enhance the communication of complex

scientific concepts. Because it is s a Webenabled technology, anyone can access

these information products from any

Internet connection and interact with the

data as a 3-D information space.

Information

For additional information, contact:

Kevin W. Laurent

12201 Sunrise Valley Drive, MS807

Reston, VA, 20192

E-mail: klaurent@usgs.gov

Internet: virtual.er.usgs.gov

For information on other USGS products

and services, call 1-888-ASK-USGS, or

visit the general interest publications Web

site on mapping, geography, and related

topics at erg.usgs.gov/isb/pubs/pubslists/.

For additional information, visit the

ask.usgs.gov Web site or the USGS home

page at www.usgs.gov.

U.S. Department of the Interior

U.S. Geological Survey USGS Fact Sheet 106-98

September 1998

Explore the Virtual Side of Earth Science

The island of Hawaii hosts both active and dormant

volcanoes, including Mauna Loa, Kilauea, and Loihi. This

model represents the location of over 27,000 earthquake

events recorded over a period of almost 30 years.

A model of Mount St. Helens, a volcano in Washington

State, before and after its May 18, 1980, eruption.