Using ODP boreholes for studying sub-seafloor hydrogeology: Results from the first decade of CORK observations
Bibliographic record
Abstract
A system for sealing and instrumenting ODP boreholes was developed 10 years ago to allow interstitial fluids to be sampled, and natural fluid pressures and temperatures to be monitored over long periods of time. The capabilities of these CORK (Circulation Obviation Retrofit Kit) observatories have been expanded recently to allow monitoring and sampling in multiple isolated horizons, and to allow installations to be completed by wireline in previously drilled holes. To date, 16 hydrologie observatory sites have been established in ridge crest, ridge flank, and accretionary prism settings. Observations at these sites have provided precise constraints on the primary driving forces for, and thermal consequences of, sub-seafloor fluid flow caused by tectonic consolidation and thermal buoyancy. Deep in accretionary prisms, high formation pressures have been observed, confirming that plate boundary faults possess little strength. In young ocean crustal settings, surprisingly low lateral temperature and pressure gradients have been documented, implying that the extrusive rocks of the oceanic crust permit efficient fluid, heat,and chemical transport over distances of many kilometres. CORK observations have also revealed pressure variations and associated fluid flow resulting from coseismic plate deformation, and from tidal, oceanographic, and barometric loading of the seafloor. The characteristics of the formation response to seafloor loading provide constraints on elastic and hydrologic properties, and allow quantitative estimates of crustal strain to be made from tectonic-strain-related pressure transients. Strain events have been observed up to 150 km away from several seismogenic dislocations along transform and seafloor spreading plate boundaries. Resume Un systeme d'instrumentation et de scellement des puits de forage du PSFM (Programme de sondage des fonds marins) a ete mise au point il y a 10 ans pour permettre l'echantillonnage des fluides interstitiels ainsi que la mesure suivie de la temperature et de la pression des fluides sur de longues periodes. Les possibilites d'observation offertes par ces trousses d'obturation retro-installees (TOR) ont ete ameliorees afin de permettre la mesure en continu et l'echantillonnage de multiples horizons isoles, et d'en permettre l'installation par filin dans les puits existants. A ce jour, 16 sites d'observation de ce genre ont ete installes dans des environnements de dorsales, la crete et le flanc, et de prismes d'accretion. Les observations realisees sur ces sites ont fourni des balises precises quant a l'action des forces premieres en jeu et les repercussions thermiques des mouvements de fluides sous les planchers oceaniques causes par la consolidation tectonique et la poussee thermique. Dans les profondeurs des prismes d'accretion, on a mesure de forte pressions, ce qui confirme que les failles bordieres des plaques n'ont que peu d'effet. Dans le contexte de croutes marine jeunes, on a note l'existence de gradients thermiques et de pressions etonnamment faibles, ce qui implique que les roches extrusives de la croute oceanique permettent un mouvement thermique, calorique et fluidique efficace sur des distances de bien des kilometres. Les observations TOR ont egalement permis de decouvrir que des variations de pression avec leurs mouvements de fluides associes etaient causes par la deformation tectonique co-seismique de la plaque, ainsi que de la charge oceanographique, barometrique et tidal du plancher oceanique. Les caracteristiques de la reaction de la formation a la charge sur le fond oceanique permettent de circonscrire les proprietes elastiques et hydro logiques, et permettent des estimations quantitatives de la contrainte crustale a partir des transitoires de pression resultant de contraintes tectoniques. Des evenements deformants ont ete observes jusqu'a 150 km du Heu de plusieurs dislocations seismogeniques le long de frontieres de transformation et d'expansion oceanique.
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 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 | 0.001 |
| Science and technology studies | 0.001 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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".