Dark Fiber: Using Sensors Beneath Our Feet to Tell Us About Earthquakes, Water, and Other Geophysical Phenomenon

Scientists have shown for the first time that dark fiber – the vast network of unused fiber-optic cables installed throughout the country and the world – can be used as sensors for detecting earthquakes, the presence of groundwater, changes in permafrost conditions, and a variety of other subsurface activity.

Late Neoproterozoic–Early Palaeozoic stratigraphic succession, Western Himalaya, North Pakistan: Detrital zircon provenance and tectonic implications

This paper presents the first ever detrital zircon U–Pb–Hf isotopic study for the Late Neoproterozoic–Early Palaeozoic stratigraphic succession exposed in the Hazara Basin, Western Himalaya, North Pakistan. This time span represents the break-up of the supercontinent Rodinia and final assembly of Gondwana. The detrital record of the Late Neoproterozoic succession indicates well-mixed detritus shed from within the Indian Craton, especially the Central Indian provenance (including the Delhi Fold Belt, Aravalli Orogen, and Bundlekhand Craton). The εHf(t) values are mostly negative, and Hf TDMC ages are clustered at 2.0–2.4 Ga, which indicates the derivation from an ancient reworked crustal source. In addition, the presence of a few positive εHf(t) values in the Late Neoproterozoic sequence indicates addition of the juvenile crust that corresponds to the period of the Rodinia break-up. However, dissimilarities with detrital signatures from the Australian continent may indicate break-up of the Rodinia supercontinent and detachment of Australia from India prior to ~754 Ma, which is the depositional age of the Hazara Formation. In addition, the angular unconformity at the base of the Abbottabad Formation represents the compressional tectonics that might be associated with the Pan-African (Indo-Antarctic Craton collision with the East African Orogen during 800–700 Ma) orogeny. The presence of the metamorphism and deformation in the rocks below the unconformity supports such an event prior to deposition of the Early Palaeozoic Abbottabad Formation. Similarly, the appearance of the Pan-African detritus in the Early Palaeozoic Abbottabad Formation could be due to closure of the ocean basin between Eastern and Western Gondwana along the Mozambique Suture. This provenance change may indicate the final assembly of supercontinent Gondwana.