The passage discusses the dangers and unexpected effects of glaciers. It begins with the story of a massive tsunami that occurred in a Peruvian lake in 2010, which was triggered by a huge block of ice breaking off from a glacier. The author explains that glaciers can be hazardous, causing tsunamis, landslides, and damage to infrastructure.
The text also explores the unique properties of ice, noting that it can be considered a rock and, under extreme pressure, can even become a metal. The author discusses the role of glaciers in regulating the Earth's climate, reflecting solar radiation, and storing ancient air and historical records.
The passage highlights the importance of glaciers as "archives" that contain information about past events, including temperature changes, volcanic eruptions, and human activities such as lead mining and smelting. The author notes that ice cores from Greenland contain records of lead pollution dating back to the Roman Empire.
Overall, the passage aims to raise awareness about the significance and potential dangers of glaciers, while also showcasing their fascinating properties and the valuable information they hold about the Earth's history.
Here are the key facts extracted from the text:
1. In 2010, a powerful tsunami occurred in a Peruvian lake called Laguna 513.
2. The tsunami was 23 meters high and caused significant damage to nearby cities.
3. The tsunami was triggered by a huge piece of ice that broke off from a glacier and fell into the lake.
4. The block of ice was the size of 15 or 20 football fields.
5. The ice tsunami destroyed a dam, 50 houses, and a water processing plant that served 60,000 residents.
6. A similar event occurred in Alaska in 2015, where a powerful wave, 492 feet high, was triggered by a glacier.
7. Glaciers can cause tsunamis through landslides, which are becoming more frequent due to global warming.
8. If all the ice on the planet were to melt, the water level would rise, and a series of strong tsunamis could occur.
9. Glaciers reflect about 90% of solar radiation, helping to cool the planet.
10. When ice melts, it exposes a darker surface that absorbs more solar radiation, contributing to global warming.
11. Glaciers act as a shield for the planet, reflecting excess radiation and helping to regulate the climate.
12. The ice reserves on our planet also act as a gigantic store of memory, containing information about past events.
13. The composition of ice can tell us about the temperature at which it was formed, the presence of dust and pollen, and even the air quality of the past.
14. Glaciers contain ancient, unaltered air that is sealed in bubbles, providing a record of the past atmosphere.
15. Lead contamination has been found in the ice of Greenland, caused by the Roman Empire's extraction and smelting of lead and silver between 1100 BC and 800 AD.
16. The amount of lead in the ice varied depending on historical events such as wars, political instability, and currency exchange.
17. Ice even has records of major plagues during these periods, with lead extraction decreasing during times of instability.