High <sup>3</sup>He emanations from the source regions of recent large earthquakes, central Japan
Bibliographic record
Abstract
Recently, two shallow M W 6.6 inland earthquakes, the 2004 mid‐Niigata prefecture earthquake and the 2007 Niigataken Chuetsu‐oki earthquake, occurred in the Niigata sedimentary basin near the boundary between the Eurasian and the North American Plates. In order to elucidate the geographic distribution of the 3 He/ 4 He ratios in and around the seismic source regions, new helium isotope data from hot spring gases and water samples from much denser sampling than in previous studies were determined. Although temporal changes in the 3 He/ 4 He ratios obtained from each well were unknown before and after the earthquakes, higher 3 He/ 4 He ratios were observed in the earthquake source regions compared to other regions. Geochemical evidence for the presence of hot spring gases and natural gases with anomalously high 3 He/ 4 He ratios (>3.8 R A ) indicates infiltration of mantle fluids derived from the subcrustal lithosphere. A plausible source of mantle helium can be attributed to upward mobilization of aqueous fluids generated by dehydration of the subducting Pacific Plate slab, resulting in the acquisition of primordial helium from a mantle wedge as the fluids into the crust. In addition, aqueous fluids may raise the Earth's surface along permeable conduits leading to the reactivation of high‐angle inverted normal faults and the triggering of recent earthquakes.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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 teacher head, 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".