Back to Earth Sciences
Alt text / descriptions for slideshow images
SlideShow: Welcome to the Earth Sciences Department webpage.
Welcome to the Earth Sciences Department webpage. Alt text provided via a
link below. The slideshow consists of 17 images showing various geologic and
atmospheric events and features.
Slide 0 : One of the most impressive geological formations in the eastern
United States, the Whaleback Anticline near Shamokin, Pennsylvania, is a
superb natural laboratory for geologists and geology students studying the
dynamic forces that shaped the planet.
Slide 1 : Most people wouldn't think to vacation in eastern Nevada, but you
can find air as cool as any Las Vegas casino in the Caves sections of
Cathedral Gorge State Park. The Caves aren't true caves but rather narrow
canyons eroded from a Pliocene Epoch lake bed.
Slide 2 : Wave: Welcome to Oceanography
Slide 3 : Big wave crashing, west coast California, CA.
Slide 4 : 40 wave in Hawaii
Slide 5 : Welcome to Geology, volcano and lightning.
Slide 6 : Poas Volcano Crater, shown above, is located in Poas Volcano
National Park in Costa Rica: acid lake?
Find out more about the acid lake
Slide 7 : California Cavern: Learn how stalactites form.
Slide 8 : Globe: Welcome to Geography
Slide 9 : NASA scientists use remote sensing to observe a section of the
earth each orbit, and then combine the data from many orbits to recreate
the whole earth at once. Sensors in space observe the earth in many
different wavelengths of light. Combinations of these images can be used
to determine what is growing in each patch of the earth, and even if it
is healthy or not. As sensors get better and more sensitive, the size of
the smallest patch that can be observed from space gets smaller and
smaller - to within a few meters now. Remote sensing data can be used in
estimating biomass, soil moisture, changes in elevation, or even animal
The photo above showing lenticular wave clouds seemingly emanating from the
snow-covered summit of Mount St. Helens in southwestern Washington was taken
on October 22, 2007. Lenticular clouds are observed when stable air near
saturation is forced to flow over mountain ranges, elevated plateaus or high
hills. The lifting cools the air to the saturation point thus forming
clouds. Lenticulars appear stationary because they're confined to wave
crests, which often migrate quite slowly. Photo taken from the U.S. Forest
Slide 10 : Volcano exploding
Slide 11 : Welcome to Meteorology, cloud.
Slide 12 : Image of a fabulous solar corona while traveling south from
Aberdeen to Glasgow, Scotland, on September 8, 2007. A thick, low-level
covering of clouds had just cleared, leaving a thinner veil of mid-level
clouds, composed chiefly of water droplets. Minute but very uniform water
droplets near the edges of these clouds deflected the Sun's light by the
process of diffraction in such a way to produce the vivid metallic colors
Slide 13 : Waves breaking over a wall on the shore.
Slide 14 : This is a photo of Logan Pass in Glacier National Park, Montana.
Many of the glaciers in this beautiful park have been noticeably receding,
but the effects of the glacial ice that nearly covered this corner of
northwestern Montana are quite obvious.
Slide 15 : Natural wonders, balancing rocks.
Slide 16 : This is a fascinating photo of the "bathtub ring" that represents
a water dipstick for the southwestern U.S. and northern Mexico. The boaters
are motoring south on the Overton Arm of Lake Mead. The white calcium
deposit you see is the 65-year-old water line that is considered the lake's
normal water level. At this particular spot, the water level is almost 50
feet (15 m) below the lake's capacity. As of October 12, 2007, Lake Mead
storage was 48% of capacity.
Slide 17: Glaciers are abundant in south-central Alaska's Prince William
Sound. One showcase glacier is Surprise Glacier, shown above. Note its
bluish ice formations. Is glacier ice really blue? No, it just appears to be
blue because the longer wavelengths of light (reds and yellows) are more
readily absorbed by thick ice than are the shorter wavelengths (blues and
greens). Thus, the longer light travels in ice, the bluer it appears. In
contrast to thick ice, sunlight does not penetrate very far into snow,
therefore it appears white. However, when you poke a hole into deep, fresh
snow (more than about 0.3 m or 1 ft in depth), bluish light will emerge