Author | Lightnews

Geoscopy — Geology Explained @geoscopy.bsky.social · 4d

🔥 Recent thrill: Episode 35 (Oct 17–18) was jaw-dropping. Two vents in Halemaʻumaʻu Crater unleashed lava fountains ~1,500 ft and ~1,100 ft high – higher than a skyscraper! It was the highest twin fountain event of this eruption so far.

1

Geoscopy — Geology Explained @geoscopy.bsky.social · 4d

⏳ How it works: Magma pressure builds for days, then suddenly boom – a lava fountain bursts out, then pauses. The volcano’s summit inflates (swells) between bursts and deflates when lava erupts

2

Geoscopy — Geology Explained @geoscopy.bsky.social · 4d

🌋 Kīlauea is showing off again! This Hawaiian volcano – one of the world’s most active – has been erupting in an unusual stop-and-go style #Geology

1 4 8

Geoscopy — Geology Explained @geoscopy.bsky.social · 5d

Fluids can rewrite chemistry (metasomatism). Picture a French dip: juices move through and change flavor without turning the sandwich to soup. Classic result at magma–limestone boundaries: skarn.

2

Geoscopy — Geology Explained @geoscopy.bsky.social · 5d

Metamorphic is the panini. Take an existing rock, heat it, squeeze it, move fluids through it—but don’t melt it. Minerals recrystallize, align, or swap elements. Same ingredients, new texture and strength.

1 3

Geoscopy — Geology Explained @geoscopy.bsky.social · 5d

Bread matters: open, airy crumb (ciabatta) is like high‑porosity sandstone—fluids can move. Dense rye is shale—good seal, lousy flow. That’s aquifers and reservoirs in lunch form.

1 1

Geoscopy — Geology Explained @geoscopy.bsky.social · 5d

Grain size tracks energy:
• Sandstone: beach/river bar—like a well‑sorted turkey sub.
• Shale: quiet water mud—more like a smooth hummus wrap.
• Conglomerate: debris flow—think a Sloppy Joe with everything.

1 1

Geoscopy — Geology Explained @geoscopy.bsky.social · 5d

Texture tells the story. Big rounded chunks → conglomerate (imagine meatballs in a roll: high‑energy river moved them far). Angular chunks → breccia (more like chopped croutons dumped in—short, sudden drop).

1 1

Geoscopy — Geology Explained @geoscopy.bsky.social · 5d

Start with sedimentary—the deli sub. Bits of older rock, shells, or crystals settle out of water or air, get compacted, then “glued” by minerals like calcite or silica. That glue is the mayo/cheese that sets.

1 1

Geoscopy — Geology Explained @geoscopy.bsky.social · 5d

Let's explain rocks by sandwiches. Trust me. Earth builds rock three main ways: it stacks, it cools from melt, or it presses and reheats what it already made. #Geology 🧵

4 14 61

Geoscopy — Geology Explained @geoscopy.bsky.social · 9d

I love the name: Pythia was the oracle at Delphi, perched above a crack in the Earth breathing strange gases to “see” the future. Here, a literal crack is venting fluid that helps us see the state of a dangerous fault. Perfect.

Geoscopy — Geology Explained @geoscopy.bsky.social · 9d

The site is unlike any seep described on active margins: warm, high‑flux, water‑dominated, not methane‑dominated. Its chemistry + temperature point to fluids percolating up through fault‑controlled pathways—basically the fault exhaling.

1

Geoscopy — Geology Explained @geoscopy.bsky.social · 9d

Translation: if the fault bleeds out its lubricant, parts of Cascadia can clamp down more tightly. Locked patches are the ones that snap in great earthquakes. The discovery gives us a direct window into that hidden pressure system.

1

Geoscopy — Geology Explained @geoscopy.bsky.social · 9d

Why this matters: fluids at a megathrust aren’t just “wet.” They control friction. High fluid pressure can help plates creep; losing fluid can let the fault lock harder, storing more strain for a bigger quake later.

1

Geoscopy — Geology Explained @geoscopy.bsky.social · 9d

The water is ~9 °C warmer than the surrounding ocean and laced with elements (boron, lithium, etc.) that scream “deep origin.” Best evidence says it’s coming from ~4 km (~2.5 mi) below the seafloor—the actual plate boundary zone. That’s… wild.

1

Geoscopy — Geology Explained @geoscopy.bsky.social · 9d

Where? ~50 miles off Newport, Oregon. A research ship spotted weird bubble plumes on sonar during a weather delay, sent down a robot, and found water jetting from the seafloor. Not a typical hydrothermal vent; the fluid chemistry is totally different.

1

Geoscopy — Geology Explained @geoscopy.bsky.social · 9d

There’s a literal leak at the bottom of the Pacific Ocean—plugged straight into the Cascadia megathrust. Scientists call it Pythia’s Oasis. It’s a spring on the seafloor that shoots out warm, almost‑fresh water like a firehose. Yes, from right above the fault. #Geology🧵

1 1

Geoscopy — Geology Explained @geoscopy.bsky.social · 9d

That's no mere rolling rock—it's a "volcanic bomb" launched from the La Palma vent like a cannonball. This molten boulder hit the steep ash cone and just kept rolling, carving a path for over a kilometer. Geologists dubbed these terrifying projectiles "spallation bombs."

1 1

Geoscopy — Geology Explained @geoscopy.bsky.social · 10d

Earth—Patch Notes v4.56 Ga

– Fixed supercontinent crash loop (not a bug, a feature).
– Magnetic field auto‑renewal improved.
– Rift DLC now ships with passive margins.
– Ocean balance: fewer BIF drops, more plankton.
– Known issue: roads vs. landslides.

1

Geoscopy — Geology Explained @geoscopy.bsky.social · 10d

Rocks keep tiny compasses. When they cooled, iron minerals locked in whatever “north” was trending. Lay them across the seafloor and you get zebra stripes of magnetic nostalgia. My phone can’t remember yesterday’s Wi‑Fi. #Geology

3

Geoscopy — Geology Explained @geoscopy.bsky.social · 10d

In my opinion the problem with Jurassic Park isn’t cloning dinosaurs. It’s building on a tropical island with that many steep slopes and zero landslide mitigation. #Geology

Geoscopy — Geology Explained @geoscopy.bsky.social · 10d

Just how “cool” is ~510 °C lava? It’s still dangerous – extremely hot – but not the instant incineration of 1100 °C lava. In fact, in 2007 a guide fell into an active lava flow at Ol Doinyo Lengai and managed to climb out and survive (with serious burns to his legs).

1 1

Geoscopy — Geology Explained @geoscopy.bsky.social · 10d

But wait what happens after. Fresh flows are dark brown/black, but within days or even hours they turn white like snow! The lava’s sodium- and potassium-carbonate minerals rapidly react with moisture in the air (or rain), forming a white coating of natron/trona (basically soda ash) as it cools.

1

Geoscopy — Geology Explained @geoscopy.bsky.social · 10d

With so little silica to thicken it, Lengai’s lava is super runny. It’s actually the most fluid lava known – racing down at up to 1–5 m/s (meters per second). That’s like watching a stream of black water or oil instead of the usual slow ooze.

1

Geoscopy — Geology Explained @geoscopy.bsky.social · 10d

Why so cool? It’s about its composition. Typical lava is rich in silica (SiO₂), but Lengai’s magma has under 3% (incredible, since even runny basalt is ~45% silica). In place of silica, it’s mostly carbonates – think minerals like those in limestone or baking soda. It’s basically molten soda ash.

1 1