Abstract Tracking methane transport becomes more complicated in the deep ocean where seafloor release of methane gas bubbles occurs at the high pressures and low temperatures conducive to hydrate formation on bubble surfaces. Gas hydrate formation can make the bubble surface rigid, preventing the dynamic interplay between bubble size, shape and rise velocity that gas‐transport models commonly rely upon when using bubble size to predict bubble rise velocity. To better constrain gas‐transport model predictions, we conducted controlled laboratory measurements of rise velocity, , for hydrate‐free air, methane, and xenon bubbles and hydrate‐coated xenon bubbles. Experimental results for were compared to predicted values from several published parameterizations used to study dissolution of gas bubbles rising in the ocean. For both hydrate‐free and hydrate‐coated gas bubbles, the McGinnis et al. (2006), https://doi.org/10.1029/2005jc003183 parameterization provides the most accurate predictions.

Abstract Northern Andean volcanism is characterized by an intense Quaternary activity, whose onshore deposits have partly covered Mio‐Pliocene products associated with the early development of the arc, making it difficult to obtain an exhaustive catalog of past eruptions. To improve our knowledge of the largest eruptions that occurred in the Northern Andean arc, we analyzed several cores from drilling sites off Ecuador to seek tephra records. We characterize for the first time the mineralogical and geochemical characteristics of tephra beds recorded in the southern part of the Panamá Basin in the sediments of DSDP and ODP drilling Sites 504, 677, 678, 1238, 1239 and 1240. We show that products of at least 27 major eruptions from the Northern Andes have reached the Pacific Ocean since the Early Pliocene, and we have correlated 11 of them between several drilling sites. Products of the oldest volcanism had mainly rhyolitic compositions belonging to a High‐K calc‐alkaline magmatic series, whereas magmas display more heterogeneous SiO 2 and K 2 O contents from the beginning of the Pleistocene. Correlations established in this work allow us to provide new temporal constraints to age models of sedimentary sequences of Sites 677, 1238 and 1240 constructed based on biostratigraphy. In addition, we show that sediments of ODP Site 1240, the closest to the Galápagos islands, recorded several Pleistocene rhyolitic eruptions associated with the hotspot's activity, possibly revealing past oceanic ridge‐hotspot interactions.