Earth's Movement

• Photoperiod Calculator 
• Here Comes the Sun!

Hydrology

• Water Science for Schools
• Surf Your Watershed 
• Everyone Needs Water 
• A Guide to Water 
• Groundwater Issues 
• Tracking Drifter Buoys 
• WaterWorks 
• Life in a Massachusetts Tide Pool 
• Department of Soil, Water, and Climate 
• National Snow and Ice Data Center 

Physical Geology

• Virtual Dating 
• Geology and Geologic Time 
• Geologic Time 
• Flints and Stones: Real Life in Prehistory 
• Introduction to Petrology: The study of rocks and their origins 
• Fossils 
• Grand Canyon Geology 
• Geology of the Mojave Preserve

Rocks and Minerals

• Atlas of Igneous and Metamorphic Rocks, Minerals, & Textures 
• Images of Rocks and Minerals 
• Smithsonian Gem & Mineral Collection 
• Minerals Information 
• The Mineral and Gemstone Kingdom 
• Rocks and Minerals Slide Show 
• The Mineral Gallery 
• World of Amber 

Weather & Climate

• National Data Buoy Center
• The Wind: Our Fierce Friend

Meteorology

• The Weather Channel
• The Online Meteorology Guide
• Storm Central
• The Tornado Project
• Franklin's Forecast
• Hurricane: Storm Science
• Weather Eye
• AccuWeather
• CNN Weather
• Historical Weather Facts
• Elements of Meterology Weather Quiz
• Elements of Meterology - Easy Questions!

Earth Forces

• Glacier 
• What are Glaciers? 
• Quiz on Glaciers and Glacial Processes 
• Cracking the Ice Age 
• USGS Earthquakes
• Volcano World 
• Volcanic Photoglossary 
• Volcano Viscosity

Topography

• Which Way is North? 
• Finding the Way 
• Images Of The Sea floor Off The U.S. Coast 
• Geological Maps 

Earth's Composition

• Understanding Our Planet Through Chemistry 

Earth's History

• Earth History Resources 
• Blast from the Past! 
• The Dinosauria 
• Zoom Dinosaurs 
• National Geographic Online's Dinosaur Eggs 
• Were Dinosaurs Good Parents?