Question
“Falls” of this substance can contaminate drinking water when its Stokes number becomes large and it decouples from the surrounding gas. For 10 points each:
[10e] Name this component of tephra whose particles are less than 2 millimeters in diameter. Volcanoes that eject these fine rocks into the stratosphere can cause a volcanic winter.
ANSWER: volcanic ash [or ashes; accept ashfall]
[10h] The next-smallest component of tephra consists of these particles that are flattened into lens-shaped fiamme (“fee-AH-may”) on the surface of welded tuff, also called ignimbrite. These particles range between 2 and 60 millimeters in diameter.
ANSWER: lapilli [or lapillus]
[10m] Tephrochronology, which uses tephra to measure the dates of past volcanic eruptions, is most accurate when the tephra is dominated by this rock due to its high potassium content. A type of magma named for this extrusive equivalent of granite is the most viscous due to its high silica content.
ANSWER: rhyolite [accept rhyolitic magma]
<Science - Other Science - Earth Science>
Summary
| 2024 ARGOS @ Brandeis | 03/22/2025 | Y | 3 | 6.67 | 33% | 33% | 0% |
| 2024 ARGOS @ Chicago | 11/23/2024 | Y | 6 | 16.67 | 100% | 33% | 33% |
| 2024 ARGOS @ Christ's College | 12/14/2024 | Y | 3 | 10.00 | 67% | 0% | 33% |
| 2024 ARGOS @ Columbia | 11/23/2024 | Y | 3 | 6.67 | 33% | 33% | 0% |
| 2024 ARGOS @ McMaster | 11/17/2024 | Y | 5 | 8.00 | 60% | 20% | 0% |
| 2024 ARGOS @ Stanford | 02/22/2025 | Y | 3 | 13.33 | 67% | 67% | 0% |
| 2024 ARGOS Online | 03/22/2025 | Y | 2 | 5.00 | 50% | 0% | 0% |
Data
| I wish it were possible to freeze time so I would never have to watch you retire | Aw we're so sorry to hear that maman died today, she gets five big booms | 0 | 0 | 0 | 0 |
| Thompson et al. | throw away your cards, rally in the streets | 10 | 0 | 0 | 10 |