Lightboard frame from Homework 1 · warm-up: Orders of magnitudeLightboard frame from Lecture 5: Patterns in the imaginaryLightboard frame from Lecture 11: Gradients in Nature's Fury
Flipped-class video series · NSF EAGERMath for the Geosciences

Short lightboard lectures on the mathematics behind geophysics: complex numbers, linear algebra, and the calculus of vector fields. Watch them before class, pause to work each step on paper, and come back to them when you review for homework and exams.

  • Short videos, most 6 to 20 minutes
  • Captions on the math lectures
  • Free to watch, no login

How to use these lectures

Watch before classEach lecture covers one idea. Watch the ones your course lists before the class that uses them.
Pause and work the boardCopy the derivation as it goes. Pause before each step and try it yourself first.
Bring questions to classClass time goes to problems and discussion, so note what confused you and ask.
Come back to reviewBefore homework and exams, jump straight to the lecture you need from your course card below.

Find your course

Each course lists the lectures to watch, in order. Instructors can link straight to a course’s list, for example #course=215.

Hurricane Isabel seen from the International Space Station
EESC 111Nature's Fury

Homework walkthroughs recorded for Nature's Fury: powers of ten, Earth's energy budget, and locating an earthquake. Lectures 11 and 12 add the pressure gradients that drive storm winds.

Map of Earth's gravity anomalies measured by NASA's GRACE satellites
EESC 214/414Earth Science Data Analysis

Fitting models to seismic and gravity data is linear algebra. Start with matrix times vector and the column space, then use complex numbers when the course turns to spectra and Fourier analysis.

Lectures32157
Cross-section of Earth showing the paths of P, S and core-phase earthquake waves
EESC 215/415Seismology and Earth Structure

The elastic wave equation is written with gradient, divergence and curl. Work through the vector-calculus lectures, which end with a derivation of the acoustic wave equation, and use complex numbers for harmonic waves.

NASA's InSight lander on Mars, which carried a seismometer
EESC 225/425Planetary Seismoacoustics

Fourier analysis, instrument response and noise spectra all run on complex numbers. Watch the complex-numbers module from the plane to the heavy lifting, then the linear-algebra lecture.

Lectures145672

The lectures

Start here

Why a short list of mathematical tools carries most of solid-Earth geophysics, and how the series fits together.

Back soon
Lecture 3Math for the geosciences: overview

The tools this series builds, and where each one shows up in seismology, data analysis and planetary science.

EESC 214EESC 215

Complex numbers

Waves and vibrations are easiest to describe with complex numbers. These lectures build the complex plane from scratch and end with the algebra used in Fourier analysis.

6 min
Lecture 1From the number line to the plane

Real numbers sit on a line; complex numbers need a plane with a real and an imaginary axis. Why, with worked problems.

EESC 214EESC 225
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Lecture 4Imaginary numbers

The imaginary unit i, the square root of minus one, and why a new class of numbers was needed at all.

EESC 225
11 min
Lecture 5Patterns in the imaginary

Powers of 2 march out along the number line, while powers of i circle back: i, −1, −i, 1. Multiplying by i is a quarter turn.

EESC 214EESC 225
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Lecture 6The geometry of complex numbers

Complex numbers as arrows with a length and an angle, and what that geometry does to multiplication.

EESC 225
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Lecture 7Complex numbers do the heavy lifting

Applications: complex exponentials turn oscillations and waves into algebra you can do by hand.

EESC 214EESC 215EESC 225

Linear algebra

Learning from data, from rock composition to imaging and machine learning, rests on systems of equations written as Ax = b.

13 min
Lecture 2Matrix times vector and the column space

Matrix–vector multiplication read as a combination of columns, leading to the column space, one of the four fundamental subspaces.

EESC 214EESC 225

Vector calculus

The calculus of fields. Gradient, divergence and curl are introduced through Maxwell's equations and the elastic wave equation, then put to work on winds, pressure and sound waves.

15 min
Lecture 8Vector calculus, express

Starts from Maxwell's equations and takes them apart, so each operator has a physical meaning before it has a definition.

EESC 215
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Lecture 9Partial derivatives and the gradient

Slopes along each axis, collected into one vector that points uphill.

EESC 215
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Lecture 10The gradient: a first example

Contours of a scalar field and the gradient that crosses them at right angles, toward the steepest increase.

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Lecture 11Gradients in Nature's Fury

A NOAA weather map: isobars, the pressure gradient, and why winds are strongest where isobars crowd together.

EESC 111
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Lecture 12Gradients, Newton's law and energy

The pressure-gradient force from Newton's second law, and how gradients connect to conservation of energy.

EESC 111
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Lecture 13Divergence of a vector field

Flux in and out of a small box: sources, sinks, and the divergence term in Maxwell's equations.

EESC 215
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Lecture 14Divergence and simple waves

Newton's law and the pressure evolution equation combine into the acoustic wave equation.

EESC 215
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Lecture 14aSimple waves: addendum

Finishes the acoustic wave equation and collects the facts used along the way.

EESC 215
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Lecture 15Curl of a vector field

Circulation around a small square, and the curl as a cross product with the del operator.

EESC 215
20 min
Lecture 16Summary: gradient, divergence and curl

How the three operators connect through del, and what each says about paths, surfaces and volumes.

EESC 215

Extra takes: Practice take: divergence (back soon) · Practice take: divergence and the electric field

Nature's Fury homework walkthroughs

Short lightboard walkthroughs recorded for Nature's Fury in spring 2021, when the course was EES 211. Each works a problem that is still on the EESC 111 homework. Three are presented by Scott Hull, then a PhD student in Miki Nakajima's group at Rochester.

16 min
Homework 1 · warm-upOrders of magnitude

Powers of ten for astronomical, planetary and economic numbers, from Avogadro's number to a billion seconds.

EESC 111
12 min
Homework 1 · sphere volumesTerra-cado: Earth as an avocado

Core as the seed, mantle as the flesh, crust as the skin: how much of Earth's volume each layer holds.

EESC 111
8 min
Homework 1 · energy from the SunDistance from the Sun and surface temperature

Solar flux falls as 1/d² and temperature goes as power to the 1/4: what Earth's 300 K surface would be at half or twice the distance.

Presented by Scott Hull

EESC 111
7 min
Homework 3 · question 4Locating an earthquake with S minus P

P waves outrun S waves, so the gap between their arrivals gives the distance to the epicenter; two stations narrow it down.

Presented by Scott Hull

EESC 111
6 min
Homework 5 · question 3Earth's temperature from black-body radiation

Balance incoming sunlight against Stefan–Boltzmann radiation to find Earth's steady-state temperature.

Presented by Scott Hull

EESC 111

About the series

I recorded these lectures in 2021 under NSF EAGER award EAR-2042007, a collaborative project with Margarete Jadamec and Erasmus Oware (University at Buffalo) and Stefany Sit (University of Illinois Chicago) to build flipped, multimodal modules for upper-level geophysics.

Lightboard lecturesThe math series on this page, captioned and free to watch.
Active-learning pollsIn-class Poll Everywhere exercises on plate tectonics, earthquakes and tsunamis, built with Ayla Martinelli ('21).
Seismologist spotlightsInterviews in which seismologists describe their career paths, from the same project.

Videos are hosted on the University of Rochester’s Panopto. Course images: Hurricane Isabel from the International Space Station (NASA Johnson Space Center); Earth's gravity anomalies from GRACE (NASA); earthquake wave paths (USGS); InSight on Mars (NASA/JPL-Caltech). All public domain, via Wikimedia Commons. Updated November 2026.