Analysis of a crater‐forming meteorite impact in Peru
Bibliographic record
Abstract
The fireball producing a crater‐forming meteorite fall near Carancas, Peru, on 15 September 2007 has been analyzed using eyewitness, seismic, and infrasound records. The meteorite impact, which produced a crater of 13.5 m diameter, is found to have released of order 1010 J of energy, equivalent to ∼2–3 tons of TNT high explosives based on infrasonic measurements. Our best fit trajectory solution places the fireball radiant at an azimuth of 82° relative to the crater, with an entry angle from the horizontal of 63°. From entry modeling and infrasonic energetics constraints, we find an initial energy for the fireball to be in the 0.06–0.32 kton TNT equivalent. The initial velocity for the meteoroid is restricted to be below 17 km/s from orbit considerations alone, while modeling suggests an even lower best fit velocity close to 12 km/s. The initial mass of the meteoroid is in the range of 3–9 tons. At impact, modeling suggests a final end mass of order a few metric tons and impact velocity in the 1.5–4 km/s range. We suggest that the formation of such a substantial crater from a chondritic mass was the result of the unusually high strength (and corresponding low degree of fragmentation in the atmosphere) of the meteoritic body. Additionally, the high altitude of the impact site (3800 m.a.s.l) resulted in an almost one order of magnitude higher impact speed than would have been the case for the same body impacting close to sea level.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.002 | 0.002 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".