Geology and Tectonics
Geologic & tectonic research at UCLA follows a tradition of excellence in the study of the growth and demise of mountain belts, basin analysis, remote sensing, and surficial processes. Our faculty and researchers combine field research with computer modeling, geochemical analysis, geochronology, petrology, and satellite image analysis to understand Earth evolution and the geologic record of plate interactions.
Planetary Science
UCLA faculty study the dynamics and physical properties of the interiors, surfaces, and atmospheres of Earth, planets, moons, and other solar system objects. We investigate the convective motions in planetary mantles and cores, the links between the microscopic-scale structure of minerals and planetary scale processes, models of plate dynamics at a range of scales, and the atmospheric, surface, and interior processes in the solar system as revealed by spacecraft missions and ground-based telescopes.
Geochemistry and Cosmochemistry
UCLA geochemists and cosmochemists explore chemical processes at scales ranging from atoms, molecules and unit cells to plate boundaries, mountain belts, whole planets, and the solar system. We seek to understand the origin of our solar system, including its connection with the interstellar medium, the processes that transformed the cloud of dust and gas surrounding the nascent sun into the building blocks of planets, the geologic processes on those early planetesimals, and their accretion to form Earth and planets.
Space Physics
UCLA is recognized internationally as a leader in the plasma physics of space. Research done by the space physics group includes data analysis, simulation, modeling, and theoretical plasma physics. Topics of interest include the dynamics of the solar wind, the magnetospheres of the Earth and planets, and the interaction of the solar wind with bodies in the solar system including asteroids, planetary satellites, unmagnetized planets, and planetary magnetospheres.
Geophysics
Our faculty are internationally recognized as some of the foremost authorities on fault mechanics, earthquake forecasting, seismic imaging, and deep earth structure. Field areas range from downtown Los Angeles to remote Siberia. Within UCLA, we work closely with specialists in tectonics, geodesy, geocomplexity, and applied mathematics to solve recalcitrant problems. We also take advantage of our special geographical location. California is a famous hotbed of earthquake research, with major collaboratories such as the Southern California Earthquake Center (SCEC) and the Jet Propulsion Laboratory (JPL). Here we need only to step outside our doors to see the objects of our research.
Geobiology
UCLA paleontologists are involved in projects spanning the entire fossil record, from the original of life to recent speciation events. Faculty and students are documenting extraordinarily slow rates of evolution among cyanobacteria; establishing and revising the classification, taxonomy and biostratigraphy of Neogene foraminifera; calculating where the iridium anomaly should be in K-T boundary sections; interpreting the evolutionary dynamics and the mechanisms of species flock formation among freshwater African gastropods; producing 3-D computer images of blastoid hydrospires; using molecular techniques to establish the relationships of the chordates and their sister groups; investigating the relationship between sea-level changes and mass extinction; reconstructing the nature and dynamics of proteins and the evolution of complexity; collecting and compiling morphometric data on North American carnivores with aims at interpreting their ecology; studying the paleobiology and paleoecology of late Cambrian molluscs of the western US; documenting the global stratigraphy and taphonomy of the Ediacaran faunas; investigating the origin of molluscs and
Department of Earth, Planetary, and Space Sciences
Recent Works (225)
Relative contributions of large-scale and wedgelet currents in the substorm current wedge.
We examined how much large-scale and localized upward and downward currents contribute to the substorm current wedge (SCW), and how they evolve over time, using the THEMIS all-sky imagers (ASIs) and ground magnetometers. One type of events is dominated by a single large-scale wedge, with upward currents over the surge and broad downward currents poleward-eastward of the surge. The other type of events is a composite of large-scale wedge and wedgelets associated with streamers, with each wedgelet having comparable intensity to the large-scale wedge currents. Among 17 auroral substorms with wide ASI coverage, the composite current type is more frequent than the single large-scale wedge type. The dawn-dusk size of each wedgelet is ~ 600 km in the ionosphere (~ 3.2 R E in the magnetotail, comparable to the flow channel size). We suggest that substorms have more than one type of SCW, and the composite current type is more frequent.
Magnetic Reconnection Inside a Flux Rope Induced by Kelvin-Helmholtz Vortices.
On 5 May 2017, MMS observed a crater-type flux rope on the dawnside tailward magnetopause with fluctuations. The boundary-normal analysis shows that the fluctuations can be attributed to nonlinear Kelvin-Helmholtz (KH) waves. Reconnection signatures such as flow reversals and Joule dissipation were identified at the leading and trailing edges of the flux rope. In particular, strong northward electron jets observed at the trailing edge indicated midlatitude reconnection associated with the 3-D structure of the KH vortex. The scale size of the flux rope, together with reconnection signatures, strongly supports the interpretation that the flux rope was generated locally by KH vortex-induced reconnection. The center of the flux rope also displayed signatures of guide-field reconnection (out-of-plane electron jets, parallel electron heating, and Joule dissipation). These signatures indicate that an interface between two interlinked flux tubes was undergoing interaction, causing a local magnetic depression, resulting in an M-shaped crater flux rope, as supported by reconstruction.