TERRASCAN — Looking Inward
0km deep<br>Surface · crust
1 / 7stop tour ✕
TERRASCAN<br>a cross-section of the living Earth
▶ Tour<br>ⓘ Guide<br>▦ Glossary<br>✦ Data<br>★ Presets
★ Open source on GitHub ↗
Your depth
0km
Surface · the crust
▶ dive to core
Layers & display
Data bodies<br>Depth slice<br>Extracted features<br>Theory gaps<br>Model<br>Surface<br>Coastlines<br>Countries<br>Labels<br>Footprints<br>Experiments<br>Spin<br>Drill-zoom exp<br>Cutaway (drop above)<br>Relief peel exp
focus · surface ⟷ interior
raw dials<br>surface
relief opacity
relief brightness
coastlines
scan slice
slice strength
anomaly gain
coverage floor
model · subsurface
model intensity
model haze
data bodies (the measured mesh)
data opacity
extracted features
feature opacity
glow
size
survey link
focus depth-of-field
Radial values: real PREM. Lateral features: a faithful synthesis of published tomography. full explainer →
The scan — what you're seeing
speed anomaly<br>feature type
14 real tomography models, combined live.
Colour = how fast seismic waves travel = the rock's temperature & stiffness . Motion (sinking / rising) is inferred from that — it is not a direct movement reading.
slow / hotaveragefast / cold
Blue = fast → cold, stiff rock, usually sinking (slabs)
Red = slow → hot, soft rock, usually rising (plumes, piles)
Neutral = ordinary average mantle — measured, nothing unusual (not “static”)
Hatched / faint = no readings — theory's guess only, not measured
subducted slab (cold)
LLSVP — giant hot pile
ULVZ — melt at the core
mantle plume (hot)
cratonic root (cold)
ridge / rift (hot)
Same data, coloured by what the feature is rather than its speed.
At this depth
The scan picks out
Conditions
temperature
—pressure
—density
—shear speed<br>baseline
how well we've scanned here—
solid scan coverage
What we know here
Data pipeline
Model inputs
all S<br>all P
normalize models<br>clustering
threshold0.50
smooth0.30
agreement min0.40
visualization
Surfaces<br>Volume<br>Points<br>Wire
A THIRD MAP OF THE EARTH<br>You're looking inside the planet.
Ordinary globes show the outside — coastlines, borders, terrain. This one looks inward. As you slide the depth control down, you cut a horizontal slice through the Earth and see two things stacked on top of each other:
① THE SCAN — sharp
What earthquakes reveal: how fast seismic waves travel at this depth — i.e. how hot/cold & stiff the rock is. (Colour shows temperature, not motion; we infer sinking/rising from it.)
Red = slower → hotter, softer, rising
Blue = faster → colder, stiffer, sinking
Faint = we've barely scanned here
② THE MODEL — blurry
Behind the scan glows the textbook Earth: the smooth, layered reference model (PREM). It's deliberately out of focus — a prediction, not an observation.
Where the scan has no coverage (especially the deep core), the blurry model brightens and takes over . That hand-off is the whole idea.
③ THE 3-D BODIES — how they're derived
Data bodies come straight from the measurements: the 14 tomography models are averaged on a (lon, lat, depth) grid, lightly smoothed, kept only where the models agree, then meshed into 3-D form (surfaces / volume / points / wire) at a chosen anomaly threshold — blue = fast/cold, red = slow/hot. Tune all of this in the Data-pipeline panel.
Extracted features are an interpretation, not derived from those models: hand-curated named structures (slabs, LLSVPs, plumes, cratons, ridges) placed at their published locations from the literature. So a plume won't sit exactly on the data's red blob — they're two different things. The survey-link dial fades each feature toward how strongly the measured ensemble actually supports it there.
▶ Take the 60-second tour<br>Explore on my own
Drag to orbit · scroll to zoom · click a boundary to jump there · hover a body for info, click to isolate it. Coastlines: Natural Earth. Reference model: PREM (Dziewonski & Anderson 1981). Built with three.js.
HOW WE KNOW<br>Everything public that maps the Earth's inside
We have never drilled past ~12 km. Everything deeper is inferred — mostly from earthquakes, plus gravity, magnetism, tiny particles, and lab physics. These are the public datasets & models behind that inference.
gathering sources…
FIELD GUIDE<br>What are these features?
A quick taxonomy of what lives inside the Earth. Blue = fast = cold/stiff ; red = slow = hot/soft . "Motion" is inferred from temperature, not measured.
CONFIGURATIONS<br>Presets
Save the whole current view — depth, every layer, all dials, the data pipeline & enabled models — under a name. Click one to restore it; ★ sets the default that loads automatically. Or copy a share link to send a view to someone.
no presets yet — save the current view below
Save preset
⧉ Copy share link
← back to the globe
depth—
signal—
DATA SOURCES—
isolated here, still in the Earth's frame — its surface footprint is lit · drag to orbit · Esc or “back” to return
CALIBRATING TOMOGRAPHY
This visualisation needs JavaScript & WebGL.