Earth science calculators
Geodesy, seismology, atmospheric, and ocean hazard estimates.
Earth-science calculators on pancalc support geodesy, sun position, tsunami speed estimates, and related coursework. Each page names constants and simplifying geometry used in the model.
Use them for teaching and order-of-magnitude checks. Survey-grade or safety-critical work requires instruments and methods beyond a web calculator.
Document coordinates, datums, and units when sharing results across teams.
5 calculators
Earth Curvature Calculator
Hidden height below horizon and drop from distance over a spherical Earth. Use the calculator above. Use the calculator above. Free browser tool.
Earthquake Energy Comparison
Energy ratio between two Richter magnitudes (log10 energy scale). Use the calculator above. Use the calculator above. Free browser tool.
Geodesic Distance & Azimuth Calculator
Haversine great-circle distance and initial bearing between two lat/lon points. Use the calculator above. Free browser tool. Free browser tool.
Sun Position Calculator
Simplified solar elevation from latitude, declination, and hour angle. Use the calculator above. Use the calculator above. Free browser tool.
Tsunami Speed & Arrival Calculator
Shallow-water wave speed √(g×depth) and arrival time from distance. Use the calculator above. Use the calculator above. Free browser tool.