![]() One of them is the long term paleoseismic history, which we are working on in a linked NSF funded project looking at turbidites as a proxy for earthquakes. The earthquake probability is also a long term goal that requires many bricks be put in place. Nobody is sure at all how in the heck that works, but that was one of the goals of this project, to start getting at things like that, we have to first map what is there, and that really hadn't been done. The region the fault traverses was formerly a subduction zone, and as the triple junction moves north, there is some "conversion" between the former subduction zone (Cascadia) and the newly lengthening San Andreas. The transform system is composed of a broad system of faults, the main part of which is presently the San Andreas, which carries about half the plate motion. There are some great animations of this at: Since then, the Mendocino Triple Junction has been migrating northward, and the transform system connecting the Juan de Fuca-Gorda Ridge system to the east Pacific Rise has lengthened. The transform system was formed about 27 Ma when the Pacific-Farallon ridge was subducted near what is now Southern California. Thanks for the great questions! We already know quite a bit about the San Andreas, for example the fault has always been a right-lateral strike slip fault. Question from: Michele, UNH geology student Will the current research being undertaken be able to determine if this was the case in the distant geologic past perhaps at the time the fault was formed? Was the San Andreas fault always a right lateral strike slip or did it exist as another fault that evolved as the tectonic plates shifted over time? I am also interested in the data that will be used to help determine earthquake probability, if any, that your team hopes to uncover from this exciting study. Recently we have been studying different fault types and my understanding is the San Andreas Fault is currently a right lateral strike slip fault. ![]() I am currently a Geology undergraduate at the University of New Hampshire. Diversity, Equity, Inclusion, and Accessibility.Primitive spiny turbots include equal numbers of right- and left-sided individuals, and are generally more symmetric than other families. ![]() In some families of flatfish, the eyes are always on the right side of the body ( dextral or right-eyed flatfish), and in others, they are always on the left ( sinistral or left-eyed flatfish). The most obvious characteristic of flatfish, other than their flatness, is their asymmetric morphology: both eyes are on the same side of the head in the adult fish. Flatfish European flounder, like other flatfish, experience an eye migration during their lifetime, making them asymmetric. ![]() Very few species show an even mixture of dextral and sinistral individuals (for example, Amphidromus perversus). A small minority of species and genera have shells in which the coils are almost always sinistral (left-handed). Over 90% of gastropod species have shells in which the direction of the coil is dextral (right-handed). Gastropods īecause the coiled shells of gastropods are asymmetric, they possess a quality called chirality–the "handedness" of an asymmetric structure. Right: The normally dextral (right-handed) shell of Neptunea despecta, a similar species found mainly in the Southern Hemisphere. Therefore, a symmetric object has sinistral and dextral directions arbitrarily defined by the position of the observer, while an asymmetric object that shows chirality may have sinistral and dextral directions defined by characteristics of the object, regardless of the position of the observer.īiology Left: The normally sinistral (left-handed) shell of Neptunea angulata, a species of sea snail (now extinct) found mainly in the Northern Hemisphere. Chirality, however, is observer-independent: no matter how one looks at a right-hand screw thread, it remains different from a left-hand screw thread. Relative direction is from the point of view of the observer a completely symmetric object has a left side and a right side, from the observer's point of view, if the top and bottom and direction of observation are defined. Relative direction and chirality are distinct concepts. Other disciplines use different terms (such as dextro- and laevo-rotary in chemistry, or clockwise and anticlockwise in physics) or simply use left and right (as in anatomy). The terms are derived from the Latin words for "left" ( sinister) and "right" ( dexter). Sinistral and dextral, in some scientific fields, are the two types of chirality (" handedness") or relative direction. Not to be confused with dexter and sinister.
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