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Place 03 · The Galápagos · Wrap-up
The Islands That Keep Changing
The sea goes warm, the islands drift and drown, the iguanas shrink and grow back, and somehow the Galápagos keep coming back too.
About 20 minutes · 1 video · a full practice review of the whole archipelago
Look back
Seven chapters ago you did not know this
You can now
Follow a current to the equator
Winds drive the great gyres, and the cold Humboldt Current, on the eastern edge of the South Pacific loop, carries chilly water all the way to the penguins.
You can now
Find the river under the sea
About 100 m down, the Equatorial Undercurrent flows east, against the sea above it, hits the western islands and wells up cold and rich.
You can now
Read the layers of the sea
Warm, light water floats on cold, heavy water. A shallow thermocline lets upwelling tap the nutrients; a deep one starves the surface.
You can now
Explain El Niño
The trade winds weaken, warm water sloshes east, the thermocline sinks, and penguins and iguanas go hungry.
You can now
Follow El Niño around the world
The ocean and the air swing together between El Niño and La Niña, reaching Peru’s fishery, Australia’s rain and the US South. NOAA tracks it with one number.
You can now
Read an island’s age from the map
A fixed hot spot builds volcanoes in the west; the Nazca Plate carries them east at about 5 cm a year until they drown as seamounts.
You can now
Explain a shrinking iguana
In a place that keeps changing, natural selection favors whoever copes, like iguanas that shrink in lean years and grow back after.
Photos: Eugenia Remark, Diego F. Parra, Nancy Zjaba, Arnauld van Wambeke, Tomáš Malík, Francesco Ungaro / Pexels
One more thing
What the islands are worth now
National Geographic — Experience the Beauty of the Galápagos’ New Marine Sanctuary. Under the surface of a place you now understand from the currents up: this is what protection is protecting.
The islands by the numbers
- 1959 — Galápagos National Park created, covering about 97% of the islands’ land
- 1998 — Special law protects the Galápagos Marine Reserve and bans industrial fishing
- 329,475 visitors in 2023, a record (about 279,000 in 2024)
- $200 — park entry fee for most foreign visitors since August 2024, doubled from $100
Ecuador made almost all of the land a national park in 1959, UNESCO put the islands on its World Heritage List in 1978, and a special law in 1998 banned industrial fishing from the marine reserve around them. Today people pay to snorkel with sea lions and watch marine iguanas sneeze, and that money helps pay for protection. But every visitor also needs flights, boats, beds, fuel and fresh water on islands that have almost none, so the real question is carrying capacity: how many people can a fragile place hold before the thing they came to see starts to wear out?
Figures: Galápagos National Park Directorate and UNESCO World Heritage Centre.
Where you can see it for yourself
Marked trails, a licensed guide, and a lot of boobies
Put it all together
Island Review
Seven chapters, one archipelago. This review walks the whole place, from the currents to the shrinking iguanas, with a few questions that tie chapters together. Retry as often as you like. If one trips you up, the feedback names the chapter to revisit, and every chapter has its own eight-question practice set at the bottom of the page.
Practice
Island Review: the whole archipelago
Twenty questions covering all seven chapters and this page. Aim for a clean run, then you are ready to leave the islands.
Where we go next
Next stop: The Ridge and the Trench
The Nazca Plate that carries the Galápagos east has to go somewhere: off South America it dives under the continent into the Peru–Chile Trench. And to the west, new seafloor for that plate is being made along an underwater chain of volcanoes. Place 04 follows the seafloor itself, because the longest mountain range on Earth is underwater and hardly anyone has seen it.
Photo credits (Pexels): Diego F. Parra, Eugenia Remark, Nancy Zjaba, Arnauld van Wambeke, Tomáš Malík, Francesco Ungaro, Ivars.