Changes

[[GPS]] technology and data was also introduced in an effort to show with certainty the difference between the Somali Plate and the Nubian Plate.  Using the GPS data, researchers could measure the velocity of tectonic plates from their interiors.<ref name=Nocquet&Calais>Nocquet, J.-M., and E. Calais, 2003, Crustal velocity field of western Europe from permanent GPS array solutions, 1996-2001: Geophysical Journal International, vol. 154, issue 1, pp. 72–88. doi:10.1046/j.1365-246X.2003.01935.x</ref><ref name=Altamimietal>Altamimi, Z., L. Métivier, and X. Collilieux, 2012, ITRF2008 plate motion model: Journal of Geophysical Research, vol. 117, issue B7. doi:10.1029/2011JB008930</ref><ref name=Calaisetal2006ab>Calais, E., L. Dong, M. Wang, Z. Shen, and M. Vergnolle, 2006, Continental deformation in Asia from a combined GPS solution: Geophysical Research Letters, vol. 33. doi:10.1029/2006GL028433</ref>

[[GPS]] technology and data was also introduced in an effort to show with certainty the difference between the Somali Plate and the Nubian Plate.  Using the GPS data, researchers could measure the velocity of tectonic plates from their interiors.<ref name=Nocquet&Calais>Nocquet, J.-M., and E. Calais, 2003, Crustal velocity field of western Europe from permanent GPS array solutions, 1996-2001: Geophysical Journal International, vol. 154, issue 1, pp. 72–88. doi:10.1046/j.1365-246X.2003.01935.x</ref><ref name=Altamimietal>Altamimi, Z., L. Métivier, and X. Collilieux, 2012, ITRF2008 plate motion model: Journal of Geophysical Research, vol. 117, issue B7. doi:10.1029/2011JB008930</ref><ref name=Calaisetal2006ab>Calais, E., L. Dong, M. Wang, Z. Shen, and M. Vergnolle, 2006, Continental deformation in Asia from a combined GPS solution: Geophysical Research Letters, vol. 33. doi:10.1029/2006GL028433</ref>

The existence of the Lwandle Plate was first quantified using the Lwandle-Antarctica-Nubia plate circuit closure constrained by spreading rates and transform azimuths along the [[Southwest Indian Ridge]]. Mathematical plate circuit closure is attained while including the existence of Lwandle; using plate circuit closure, plate velocities can be calculated from the velocities of other plates.<ref name=H-JETAL /><ref name=Fowler>Fowler, C. M. R., 2006, The solid earth: an introduction to global geophysics, 2nd ed., Cambridge University Press. ISBN 9780521893077.</ref>

The existence of the Lwandle Plate was first quantified using the Lwandle-Antarctica-Nubia plate circuit closure constrained by spreading rates and transform [[azimuth]]s along the [[Southwest Indian Ridge]]. Mathematical plate circuit closure is attained while including the existence of Lwandle; using plate circuit closure, plate velocities can be calculated from the velocities of other plates.<ref name=H-JETAL /><ref name=Fowler>Fowler, C. M. R., 2006, The solid earth: an introduction to global geophysics, 2nd ed., Cambridge University Press. ISBN 9780521893077.</ref>

In 2008, the entire East African Rift System was successfully "quantified" through the integration of the GPS and earthquake data with the spreading rate and transform azimuth constraints.<ref name=Stampsetal />

In 2008, the entire East African Rift System was successfully "quantified" through the integration of the GPS and earthquake data with the spreading rate and transform azimuth constraints.<ref name=Stampsetal />

* '''Southern Boundary''' - The Southwest Indian Ridge, an ultra-slow [[spreading ridge]] with a slow spreading rate of about 12-18 mm/yr, acts as the southern boundary.<ref name=Saria /><ref name=H-J2005 /> This spreading ridge separates Lwandle from the Antarctic plate.<ref name=Chu&Gordon>Chu, D., and R. Gordon, 1999, Evidence for motion between Nubia and Somalia along the Southwest Indian ridge: Nature, vol. 398. doi:10.1038/18014</ref>

* '''Southern Boundary''' - The Southwest Indian Ridge, an ultra-slow [[spreading ridge]] with a slow spreading rate of about 12-18 mm/yr, acts as the southern boundary.<ref name=Saria /><ref name=H-J2005 /> This spreading ridge separates Lwandle from the Antarctic plate.<ref name=Chu&Gordon>Chu, D., and R. Gordon, 1999, Evidence for motion between Nubia and Somalia along the Southwest Indian ridge: Nature, vol. 398. doi:10.1038/18014</ref>

* '''Eastern Boundary''' - To the east, the boundary may be more of a diffuse boundary. There are current studies trying to pinpoint the exact location of this boundary; it is believed to cut across Madagascar, making it Lwandle's only boundary that is not purely oceanic. Earthquake slip vectors are the primary constraint that predict the actual plate boundaries. Velocity predicted at this boundary is 1.3-1.4 mm/yr. This boundary separates Lwandle from the Somali Plate.<ref name=Demetsetal />

* '''Eastern Boundary''' - To the east, the boundary may be more of a diffuse boundary. There are current studies trying to pinpoint the exact location of this boundary; it is believed to cut across Madagascar, making it Lwandle's only boundary that is not purely oceanic. Earthquake slip vectors are the primary constraint that predict the actual plate boundaries. Velocity predicted at this boundary is 1.3-1.4 mm/yr. This boundary separates Lwandle from the Somali Plate.<ref name=Demetsetal />

* '''Western Boundary''' - The western boundary is especially poorly understood; there is very little [[seismic activity]] along this boundary.<ref name=Hartnady /> Despite that, a misfit to a seafloor [[magnetic anomaly]] strongly suggests that motion exists.<ref name=Demetsetal /><ref name=Lemaux&Royer> Lemaux, J., R. Gordon, J.-Y. Royer, 2002, Location of the Nubia-Somalia boundary along the Southwest Indian Ridge: Geology, vol. 42, issue 10.</ref> Some models suggest it is a right-lateral strike slip boundary with a rate of about 1 mm/yr, with some extension.<ref name=Stampsetal /> Still, others even suggest that motion ceased at this boundary approximately 11 million years ago.<ref name=Patriatetal>Patriat, P., H. Sloan, and D. Sauter, 2014, From slow to ultraslow: A previously undetected event at the Southwest Indian Ridge at ca. 24 Ma: Geology, vol. 42, issue 10. doi:10.1130/G24270A.1</ref> This boundary separates Lawndale from the Nubian Plate.<ref name=Demetsetal />

* '''Western Boundary''' - The western boundary is especially poorly understood; there is very little [[seismic activity]] along this boundary.<ref name=Hartnady /> Despite that, a misfit to a seafloor [[magnetic anomaly]] strongly suggests that motion exists.<ref name=Demetsetal /><ref name=Lemaux&Royer> Lemaux, J., R. Gordon, J.-Y. Royer, 2002, Location of the Nubia-Somalia boundary along the Southwest Indian Ridge: Geology, vol. 42, issue 10.</ref> Some models suggest it is a right-[[lateral]] strike slip boundary with a rate of about 1 mm/yr, with some extension.<ref name=Stampsetal /> Still, others even suggest that motion ceased at this boundary approximately 11 million years ago.<ref name=Patriatetal>Patriat, P., H. Sloan, and D. Sauter, 2014, From slow to ultraslow: A previously undetected event at the Southwest Indian Ridge at ca. 24 Ma: Geology, vol. 42, issue 10. doi:10.1130/G24270A.1</ref> This boundary separates Lawndale from the Nubian Plate.<ref name=Demetsetal />

* '''Northern Boundary''' - Bordering the Lwandle plate to the north is the Romuva plate.<ref name=Stampsetal />

* '''Northern Boundary''' - Bordering the Lwandle plate to the north is the Romuva plate.<ref name=Stampsetal />

== Modern movements ==

== Modern movements ==

GPS data paired with earthquake slip data is used to estimate the velocity of the Lwandle Plate and its neighbors. The velocity of the Lwandlean Plate, relative to the Nubian and Somali plates, is estimated to be a very slow rate (1-2 mm/yr). With these low rates of motion, it is expected that this area wouldn't have much seismic activity. The data shows exactly that.<ref>Saria, E (April 2014). "Present-day kinematics of the East African Rift". Journal of Geophysical Research: Solid Earth 119 (4). doi:10.1002/2013JB010901</ref> Though Lwandle is moving faster relative to the Antarctic plate than to Nubian and Somali, this spreading ridge is one of the slowest on planet Earth, spreading at less than half the rate of human fingernail growth.<ref>Cheadle, Mike; John, Barbara. "Ultra Slow Spreading Ridges and Oceanic Core Complexes: Big Mountains and Bigger Faults". National Oceanic and Atmospheric Administration. Retrieved 29 October 2014.</ref> It appears that, for now, Lwandle will be in its current position for quite some time.<ref>DeMets, Charles; Gordon, Richard; Argus, Donald (2010). "Geologically current plate motions". Geophys. J. Int 1–80: 39.</ref>

GPS data paired with earthquake slip data is used to estimate the velocity of the Lwandle Plate and its neighbors. The velocity of the Lwandlean Plate, relative to the Nubian and Somali plates, is estimated to be a very slow rate (1-2 mm/yr). With these low rates of motion, it is expected that this area wouldn't have much seismic activity. The data shows exactly that.<ref name=Saria /> Though Lwandle is moving faster relative to the Antarctic plate than to Nubian and Somali, this spreading ridge is one of the slowest on planet Earth, spreading at less than half the rate of human fingernail growth.<ref name=Cheadle&John>Cheadle, M., and B. John, Ultra Slow Spreading Ridges and Oceanic Core Complexes: Big Mountains and Bigger Faults: National Oceanic and Atmospheric Administration.</ref> It appears that, for now, Lwandle will be in its current position for quite some time.<ref name=Demetsetal />

[[File:Stamps2008animatedX.jpg|center|300px|Red arrows show the relative plate velocity at that boundary.]]

[[File:Stamps2008animatedX.jpg|center|thumb|300px|Red arrows show the relative plate velocity at that boundary.]]

== See also ==

== See also ==

== References ==

== References ==

{{reflist|30em}}

{{reflist}}

[[Category:Tectonic plates]]

[[Category:Tectonic plates]]