| |
|
|
|
|
|
OUR
RESTLESS PLANET
| |
|
| |
We
live on a restless planet. Earth is continually influenced
by the sun, gravitational forces, processes emanating from
deep within the core, and by complex interactions with oceans
and atmospheres. At very short time scales we seem to be standing
on terra firma, yet many processes sculpt the surface with
changes than can be quite dramatic (earthquakes, volcanic
eruptions, landslides), sometime slow (subsidence due to aquifer
depletion), seemingly unpredictable, and often leading to
loss of life and property damage.
Accurate
diagnosis of our restless planet requires an observational
capability for precise measurement of surface change, or deformation.
Measurement of both the slow and fast deformations of Earth
are essential for improving the scientific understanding of
the physical processes, and for optimizing responses to natural
hazards, and for identifying potential risk areas. |
| |
|
| |
 |
| |
Earthquake
animation: Northridge (5 MB).
This animation is a 4D visualization of rupture and
wave propagation for the 1994 Northridge earthquake.
This rendering displays interactions between earthquake
rupture and the seismic wavefield and between the wavefield
and crustal structure, as well as the nature of surface
shaking associated with impinging P and S waves. P waves
are cyan and S waves are magenta and are superimposed
on the Vs=2.5 km/s isosurface for the San Fernando basin
and the LA basin for 25 seconds. Credit: Kim Olsen,
University of California, Santa Barbara. |
| |
| Earthquake
animation: world map (3 MB). Cumulative global
earthquake occurrences from 1960 through 1995. Earthquakes
are shown as yellow dots. Credit: NASA / Goddard Space
Flight Center Scientific Visualization Studio. |
| |
| Flood
animation: Orissa (2.3 MB). This movie, derived
from QuikSCAT/SeaWinds Scatterometer data, depicts the
1999 Orissa disaster that affected 15 million people.
Two consecutive supercyclones hit Orissa (as shown by
the wind field over ocean causing widespead coastal and
inland flooding as indicated by dark blue areas on land.
Topography contours (500-5000 m, also represented by color
from yellow to red) are overlaid on the images to reveal
the relationship of inundated areas with local topographic
characteristics. Credit: S. V. Nghiem, JPL; G. R. Brakenridge,
Dartmouth Flood Observatory, Early Flood Mapping Project,
W. Daffer, JPL. Also available is a full-size
QuickTime animation (18
MB). |
| |
| Land
subsidence animation: Las Vegas Valley (2.8 MB).
Animation of land-surface deformation of Las Vegas Valley,
Nevada, compiled from interferograms for 1992 to 1999.
Seasonal land subsidence and uplift due to ground-water
withdrawals and artificial recharge control the vertical
deformation and faults contribute to the areal extent
and patterns of deformation. Credit: U.S. Geological Survey
/ Nevada Bureau of Mines and Geology / NASA / Stanford
University. |
| |
| Land
subsidence animation: Lost Hills (5 MB).
Ground subsidence in the Belridge and Lost Hills oil fields,
near Bakersfield, California, based upon the 18 year difference
between USGS and Space Radar Topography Mission (SRTM)
Digital Elevation Models (DEMs). The image morphs between
the two DEMs and uses a Landsat image overlay. The vertical
dimension has been exaggerated by 300 times for clarity;
maximum subsidence was approximately 3 meters. Animation
by Vince Realmuto, JPL; data courtesy of Robert Crippen,
JPL. For more information contact Vince
Realmuto. |
| |
| Magnetic
dynamics animation: radial component (2 MB).
The radial component of the magnetic field at the core-mantle
boundary (CMB) is determined from Oersted observations.
Credit: Jeremy Bloxham, Harvard University. |
| |
| Sea
level changes animation: Pacifica (4 MB).
During the 1997 to 1998 El Niño season, California's
coastlines experienced severe erosion resulting in millions
of dollars worth of damage. The before and after images
above show coastal erosion near Esplanade Drive in Pacifica,
California from 1997 to 1998, from airborne laser altimetry
data. Credit: NASA/Goddard Space Flight Center Scientific
Visualization Studio. Photo courtesy of U.S. Geological
Survey. |
| |
| Sea
level changes animation: Pine Island Glacier (5 MB).
A model-based simulation of Pine Island Glacier, the most
active glacier in Antarctia. It accelerated 18% in 8 years
over a length of more than 150 km, causing ice to thin
13 m, and it's line of floatation to reterat 6 km. Animation
by Vince Realmuto, JPL; data courtesy of Eric Rignot,
JPL. For more information contact Vince
Realmuto. |
| |
| Tsunami
animation: Honolulu (5 MB). This animation
simulates tsunami inundation of the area from Wakiki beach
to downtown Honolulu after a local 7.4 earthquake. Such
simulations utilize wave propagation, runup, and inundation
computations in order to predict tsunami behavior and
determine the best evacuation routes. Credit: Gerard Fryer,
University of Hawaii at Manoa / Pacific Disaster Center
/ NASA. |
| |
Volcano
animation: Mt. Etna (4 MB).
This animation depicts ground deformation associated
with magma intrusion at Mount Etna, Italy. The steady
inflation of edifice occurred from 1993 to 1995 and
cultiminated in resumption of eruption activity in late
1995. Ground deformation data are derived from Diff.
Radar Interferometry and is represented by color contours.
Ground deformation predicted by Point Source (Mogi)
Model is represented by animated deformation of Digital
Elevation Models. Ground deformation has been exaggerated
30,000 times, and the maximum inflation of the edifice
was 12 cm. Animation by Vince Realmuto, JPL; data courtesy
of Paul Lundgren, JPL. For more information contact
Vince
Realmuto. |
| |
| Volcano
animation: Mt. Kilauea (4 MB). This Animation
shows the Kamoamoa lava flow on Mt. Kilauea in Hawaii
spreading towards the ocean. Data in the forms of visible,
infrared and thermal infrared imagery was acquired using
the NASA C-130 remote sensing research aircraft between
September 3 and 17, 1995. The combination of image and
elevation data results in the visualization of interaction
between the local topolographic gradient and the velocity
and morphology of the flows. Credit: V.J. Realmuto, S.L.
Adams, Z. Gorjian, JPL. Also available is a full-size
QuickTime animation (29 MB). For more information
contact Vince
Realmuto. |
| |
|
|
|
|
