Here is a concise summary of the text:
**Title:** Top 5 Underwater Discoveries That Cannot Be Explained
**Summary:**
1. **Baltic Sea Anomaly (2011)**: A mysterious, unexplained 60m-wide circular object with ramp-like structures detected on the seafloor.
2. **Underwater Rivers (Black Sea & Mexico)**: Naturally occurring rivers with trees, leaves, and waterfalls, defying conventional understanding.
3. **Underwater Pyramid (Azores)**: A 60m-high, 8,000 sqm pyramidal structure, possibly man-made, oriented to the four cardinal directions.
4. **"Finger of Death" (Arctic/Antarctic)**: A deadly, icy brine formation that freezes and kills sea creatures upon contact.
5. **"Loki's Castle" (Arctic)**: A recently discovered, thriving ecosystem on volcanic seamounts in extreme, hostile conditions, baffling scientists.
**Additional Context:** These unexplained discoveries highlight the vast mysteries still surrounding our ocean, which remains largely unexplored (only 3% explored to date).
Here are the key facts extracted from the text, without opinions, with each fact numbered and in short sentences:
**General Facts**
1. In 1969, humans first landed on the moon.
2. Only about 3% of the Earth's oceans have been explored.
3. Approximately 97% of the Earth's ocean depths remain unexplored.
**Underwater Discoveries**
**#5: Baltic Sea Anomaly**
4. In 2011, the "Ocean X" diving team discovered an unexplained sonar image in the Baltic Sea.
5. The image shows a 60-meter-wide circular object with features resembling ramps and stairways.
6. The team encountered electrical interference upon returning to the site in the following year.
7. Samples from the site included granite, sandstone, and an out-of-place piece of basaltic/volcanic rock.
**#4: Underwater Rivers**
8. Researchers found an underwater river in the Black Sea with currents 350 times stronger than the River Thames.
9. This river has channels, rapids, and waterfalls, similar to those on land.
10. If on land, this river system would be the sixth largest in the world.
11. A unique underwater river was also discovered in Mexico's Yucatán Peninsula, within a cenote.
12. This Mexican river has trees, leaves, and waterfalls, and is 33 meters underwater.
**#3: Underwater Pyramid**
13. A private yacht owner's equipment detected a mysterious, perfectly squared structure at a 40-meter depth.
14. The underwater pyramid is approximately 60 meters high and 8,000 square meters at its base.
15. It is located between the islands of Terceira and São Miguel.
16. The structure is oriented to the four cardinal directions (North, East, South, West).
**#2: Ice Finger of Death**
17. An "ice finger of death" is a phenomenon where icy brine water forms a descending, finger-like icicle.
18. This occurs when cold, dense brine sinks and freezes surrounding seawater.
19. Brinicles (these icy formations) are found in the Arctic and Antarctic.
20. They can be deadly to sea floor creatures due to extreme cold.
**#1: Loki's Castle**
21. Researchers from the University of Bergen discovered an entire ecosystem thriving on volcanic seamounts in the Arctic Sea.
22. This ecosystem, known as "Loki's Castle," exists in extreme, previously unexplored conditions.