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El día de hoy encontramos 5 chimeneas hidrotermales activas y observamos algunas otras inactivas. De las chimeneas activas chimeneas salía el agua caliente rica en minerales que provenía de las ventilas. Las chimeneas crecen a medida que se precipitan los minerales contenidos en esta agua caliente. Algunas de estas chimeneas llegan a tener una altura de hasta 40 pies o inclusive más y el agua caliente que estaba saliendo de una de las chimeneas que visitamos tenía una temperatura de 550° F. Desde el punto de vista biológico, estas ventilas tienen un gran valor ya que encontramos una gran variedad de organismos cuya alimentación no depende de la productividad de las aguas superficiales o de la fotosíntesis. La fotosíntesis se lleva a cabo en las aguas superficiales donde existe luz y la mayoría de los organismos que viven a profundidad dependen de esta productividad superficial para sobrevivir ya que se alimentan de los organismos que caen al fondo en la forma de nieve marina (marine snow). Sin embargo, en las ventilas hidrotermales las bacterias utilizan las aguas ricas en elementos químicos como una fuente de energía, un proceso conocido como quimiosíntesis. Estas bacterias quimiosintéticas, mantienen las poblaciones de gusanos, caracoles, cangrejos, almejas y peces. Los gusanos tubícolas gigantes que encontramos aquí no tienen una boca sino que cultivan las bacterias dentro de su cuerpo. Los gusanos proveen a las bacterias un lugar donde vivir y proporcionan oxígeno a las bacterias a través de su sangre rica en hemoglobina. A cambio de esto las bacterias nutren a los gusanos. Algunos de los gusanos gigantes que encontramos eran muy grandes; un espécimen colectado el día de hoy casi tenía 5 pies de largo! A un costado de las chimeneas, encontramos también agua expulsada por la ventilas pero no tan caliente como la encontrada en las chimeneas. En estas zonas podemos encontrar almejas visecómidas (vesicomyid clams), que también sirven como hogar de bacterias quimiosintéticas de una forma similar a las que tienen los gusanos gigantes. Muestreamos estos organismos que viven en las ventilas hidrotermales con el fin de tratar de entender la relación que existe entre las poblaciones que viven en este lugar y aquellas que viven en ventilas hidrotermales en el océano pacífico. Para determinar el grado de relación utilizamos marcadores moleculares, o regiones de genes del DNA los organismos que estamos comparando. Las herramientas moleculares también se pueden utilizar para darnos una idea de los procesos evolutivos como por ejemplo cómo y cuándo apareció una nueva especie o determinar la relación que existe entre especies similares. Por ejemplo, basándonos en estudios moleculares se ha determinado que los gusanos gigantes que encontramos viviendo en las chimeneas hidrotermales están relacionados con los gusanos devoradores de hueso (Osedax spp). Algo curioso que sucedió el día de hoy fue que encontramos fragmentos de hueso de mamífero, a pesar de que no encontramos Osedax en estos huesos, lo que si encontramos fueron algunos caracoles y una especie de mejillones pequeños. En inmersiones realizadas en el cañón submarino Monterey (Monterey Canyon) también encontramos huesos de mamífero con organismos similares a los que encontramos en la inmersión del día de hoy así que vamos a utilizar los marcadores moleculares para tratar de determinar primero si existe una relación entre estas especies y segundo, hasta que grado es esta relación. También colectamos muestras de sulfuros en las chimeneas, tanto en las activas como inactivas y determinaremos la edad de las chimeneas inactivas utilizando radio radioactivo (radioactive radium). También muestreamos uno de los flujos de lava más extensos que hemos encontrado y que es donde se encuentran las chimeneas de las que hemos estado hablando. Cuando analicemos las muestras del flujo de lava podremos evaluar los procesos de mezcla del magma en la cámara magmática que se encuentra bajo el eje de la cordillera a una profundidad de 1 a 2 km. Antes de finalizar la inmersión pudimos determinar la edad relativa de algunos flujos antiguos y los muestreamos para posteriormente determinar su edad y realizar algunos análisis químicos. La información que obtengamos definitivamente nos va a ayudar a descifrar la historia eruptiva de la cordillera Alarcón. 
Una densa comunidad de organismos crece en las chimeneas hidrotermales. Estos gigantes gusanos tubícolas pueden alcanzar 6 pies de largo y brindan alimento y hábitat a una gran variedad de gusanos, caracoles, cangrejos y peces. 
Agua caliente rica en minerales que sale de una ventila hidrotermal en el piso oceánico. También conocida como una fumarola negra (black smoker) el agua rica en minerales aparece como una columna de humo negro saliendo del piso marino. En la superficie de la fumarola podemos observar un tapete bacteriano de color blanco. 
Se puede observar una zona densamente cubierta por almejas en el fondo a un costado de la chimenea hidrotermal. 
Figura 4: Hueso de mamífero que contenía muchos caracoles y mejillones pequeños. Este tipo de organismos también fueron encontrados en un hueso de ballena recuperado del cañón submarino Monterey . Se utilizarán marcadores moleculares para determinar la relación que existe entre ambas poblaciones. —Lonny Lundsten y Dave Clague
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Volcanoes & Seamounts
Equipment
The R/V Western Flyer is a small water-plane area twin hull (SWATH) oceanographic research vessel measuring 35.6 meters long and 16.2 meters wide. It was designed and constructed for MBARI to serve as the support vessel for ROV operations. Her missions include the Monterey Bay as well as extended cruises to Hawaii, Gulf of California and the Pacific Northwest.
ROV Doc Ricketts is MBARI's next generation ROV. The system breaks new ground in providing an integrated unmanned submersible research platform, with many powerful features providing efficient, reliable and precise sampling and data collection in a wide range of missions.
A push-core looks like a clear plastic tube with a rubber handle on one end. Just as its name implies, the push core is pushed down into loose sediment using the ROV's manipulator arm. As the sediment fills up the core, water exits out the top through one-way valves. When the core is pulled up again, these valves close, which (most of the time) keeps the sediment from sliding out of the core tube. When we bring these cores back to the surface, we typically look for living animals and organic material in the sediments.
Niskin bottles are used to collect water samples as well as the tiny bacteria and plankton in that volume. The caps at both ends are open until the bottles are tripped, when the caps snap closed.
The box fits in a partition in the sample drawer. It is shown open, with an animal being placed into it by the ROV's manipulator. When the lid is closed, the box will hold water to protect the animals inside.
This device is used to collect volcanic glass fragments from the surface of a flow. It is made of about 450kg of lead and steel and is launched over the stern of the ship on a wire. Fragments of rock that break off of the lava flow on impact are trapped in wax-tipped cones mounted around the crusher. The wax is melted in the lab to liberate the rock particles for analysis.
The benthic toolsled is attached to the bottom of the ROV for our geology dives. Its components are the manipulator arm and the sample drawer. The sample drawer is shown open on deck, full of rocks. Normally it is closed when the vehicle is operating and is opened only when a sample needs to be stowed. Partitions in the drawer help us keep the rocks in order. The rocks often look alike, but the conditions and chemistries of the eruptions are different so it is important that we know where each came from.
This equipment is used to vacuum glass particles and larval animals from cracks and crevices. The carousel of small plastic jars fitted with wire mesh will be mounted in the benthic toolsled. The hose will be held by the ROV's manipulator and a suction will be drawn by the pump.
Canvas bags on a T-handle for collecting gravel or other materials that fall out of a push-core.
Held by the ROV's manipulator, the wire on the right is placed into the fluid emitted from a hydrothermal vent to record the temperature.
Vibracoring is a common technique used to obtain samples from water-saturated sediment. These corers work by attaching a motor that induces high frequency vibrations in the core liner that in turn liquefies the sediment directly around the core cutter, enabling it to pass through the sediment with little resistance. Crew
R/V Western Flyer
ROV Doc Ricketts
Research Team
Dave's research interests are nearly all related to the formation and degradation of oceanic volcanoes, particularly Hawaiian volcanoes, mid-ocean ridges, and isolated seamounts. Topics of interest include: compositions of mantle sources for basaltic magmas and conditions of melting; volatile and rare-gas components in basaltic magmas and their degassing history; chronostratigraphic studies of eruption sequence and evolution of lava chemistry during volcano growth; subsidence of ocean volcanoes and its related crustal flexure, plate deformation, and magmatic activity; geologic setting of hydrothermal activity; origin of isolated seamounts; and monitoring of magmatic, tectonic, and hydrothermal activity at submarine and subaerial volcanoes.
Jenny works with Dave Clague in the submarine volcanism project, processing the high-resolution MBARI mapping AUV data and interpreting the maps using ROV observations and samples from our research sites. On this cruise, she will stand watches in the ROV control room, help with rock and sediment sample workup and curation once the vehicle is on deck, and coordinate these cruise logs. She is now quite solidly a marine geologist, but her degrees are in biochemistry (Smith College) and biological oceanography (Oregon State University). She is thankful for the opportunities that have led her to study volcanoes, and loves being involved with the research and going to sea. She looks forward to discovering more about how Earth works.
On this cruise, Lonny will be in charge of biological sample collection and processing and video data management. This work entails identifying unique biological and geological features that will be seen during the dive, while using MBARI-designed software to log the observations. He is especially excited about this expedition, because no one has surveyed this particular seamount before, and he expects to find many new species on this cruise.
Julie works with the submarine volcanism group, where she currently produces high resolution maps of the seafloor that are used to identify geologic features along submarine ridges and seamounts. Her research interests also include modeling of volcanic ash from sub-aerial, large-scale explosive eruptions.
Ryan's work with the submarine volcanism project primarily focuses on the formation and distribution of volcaniclastic deposits on active and extinct seamounts and mid-ocean ridges. By categorizing the diversity in these deposits with respect to volcanic landforms he hopes to better understand the underlying controls on explosive vs. non-explosive deep marine eruptions. His background research on deep-marine gravity flow deposits preserved in sedimentary-volcanic successions exposed on land lends a comparable platform to study similar deposits of the modern oceans.
Julie is a Research Associate and Staff Scientist with the Institute for Rock Magnetism at the University of Minnesota. As a paleomagnetist, Julie studies variations in Earth's magnetic field and how those variations get recorded in rocks and sediments. One of Julie's particular interests involves using paleofield variations recorded in mid-ocean ridge lava flows to place age constraints on the flows. On this expedition, Julie is interested both in using this technique to try to date some of the young lava flows and in gaining a better understanding of how the Earth's field has varied in this particular location.
Pat is a Professor of Geology at the Scripps Institution of Oceanography, University of California, San Diego. His research interests include petrology and geochemistry of magmas produced within and along divergent and convergent boundaries of tectonic plates, magmatic and tectonic evolution of continental margins and mantle geodynamics. On this expedition, Pat is interested in the petrologic and tectonic evolution of the newly formed oceanic basement in the Gulf of California.
Brian studies the recent magmagenesis and petrology of the Juan de Fuca Ridge. His interest in mid-ocean ridges began during his postdoctoral fellowship with MBARI's submarine volcanism project; there, he utilized uranium-series disequilibria within individual lavas of Axial Seamount to clarify eruption and petrogenetic timescales. At mid-ocean ridge systems globally, Brian is interested in a) how variability in lava morphology, geochemistry, and petrology reflect deeper mantle-melting and magmatic processes and their complex interplay with tectonism and b) improving the chronological framework of the ridge magmatic plumbing systems. Brian received his Ph.D. in Earth and Planetary Science from Washington University in St. Louis in 2007.
Rigoberto Guardado is a teacher and research scientist with the Facultad de Ciencias Marinas (Marine Sciences Faculty) at the University of Baja California in Mexico. As a oceanographer, Rigoberto studies sedimentation processes in the ocean. On this expedition, Rigoberto is interested in learning more about the sediments in this area of the Gulf of California.
Ronald Spelz earned his Ph.D. in earth sciences from Centro de Investigación Científica y de Educación Superior de Ensenada (CICESE) in 2008. His research interests are mainly focused in the structural geology and tectonic geomorphology of fault bounded basins and mountain range-fronts in northern Baja California. He is also part of the multidisciplinary research team studying the origin and effects of the El Mayor-Cucapah 7.2 magnitude earthquake which struck northern Baja in April 4, 2010. Ronald presently works in the Marine Sciences Faculty at the Universidad Autónoma de Baja California.
Hiram Rivera is part of the Coastal Management group and teacher in the Faculty of Marine Science at Universidad Autónoma de Baja California. Since 2008 he has worked as a technician with geographic information systems (GIS) applied to fisheries resource management. From 2010 to now he has worked with his students in public participation geographic information systems (PPGIS) 3D models applied to the use of GIS to broaden public involvement in policymaking. His interest for this cruise is to learn about the techniques associated with digital cartography of the Gulf of California. |
