5 6 Arten dextraler (rechtshändiger) Transform-Störungen: a) Rücken/Rücken (die häufigste Transform Störung in ozeanischen Becken)b)/c) Rücken/Subduktiond)/e)/f) Subduktion/Subduktion ( häufige Transformstörung auf Kontinenten)z.B. San Andreas(Es gibt ebenso 6 sinistrale (linkshändige) Transform Störungen.)
19 · Inverting for the plates Euler pole Rigid plate rotation: V = Ω x r V·n = VnV·e = Ve=Vn = n ·(Ω x r) = (r x n) ·ΩVe = e ·(Ω x r) = (r x e) ·Ω(r x n)x (r x n)y (r x n)z Ωx Vn(r x e)x (r x e)y (r x e)z Ωy VeΩzInvert for Ω that minimizes residual (Vcomputed - Vobserved)Euler vector is that you can describe the motion of a point/rigid plate motion on a sphere by this vectorN and e as a local reference frameCall it not equation but system!!!QUCIKER!!!!!!!!!!!!!!! vector represents the rigid plate motionVelocity at a certain point on the plate is only dependent on a Position vecotr and the Euler vector. We can split the velocity into a north and south direction by calculating the scalar product of a northing or easting vector (on the sphere) that is dependent on the Positionvector and the Velocity. The north and east component of the velocity can than also be expressed as The scalarproduct of the northing or easting vecotr and the cross product of the Eulervector and the Positionvector. This is resulting in a Postionmartix that is known for the GPS points that is equal the observed GPS velocity in n and e direction, when the Eulervector is known. As soon as we have 2 GPS points with velocity estimates we have a indetermined system, for which we can estimate Omiga by the minimization of the difference between the computed and observed Velocity.
23 Beispiel: Mittelatlanik Relativbewegung Afrika, Südamerika wird durcheinen Pol nahe des Nordpols beschrieben.Dieser lässt sich aus der Orientierung derTransformstörungen im mittleren Atlantikbestimmen.Die Relativbewegung Amerika/Afrika ist in diesemSegment besonders groß, bedingt durch denfast 90 Grad Abstand zum Rotationspol
27 Processed GPS data for Pacific plate in IGSb00 reference frame Up to now we learned how to calculate the velocity of a station. Here we see the velocity that I calculated for all to us available GPS stations on the Pacific plate. Up to now this velocity is in IGSb00 reference frame. In order to derive a stable PA ref.frame, to which we can relate the motion of BC, we need to compute the Pacific Euler vector that describes the rigid plate motion of PA. Therefore we need to look closer to the location of the GPS station (near plate boundary in deformation zones) and the time-series quality (error ellipse). Choose sites that represent the stable plate.
28 Stable Pacific plate reference frame Stable Pacific plate reference frameResidual motion of GPS stations w.r.t. Pacfic plate Euler vectorEP for rigid PA.GPA on PA should not have any residual motion. Motion within error rigidity of PA constraint. GPSResidual motion wrt stable PA plate Euler pole (vector)How big is the standard error in terms of the ellpise.
36 Where do Eqs occur?Earthquake are release of elastic strain accumulated due to deformation.If plate are rigid must be at plate boundaries!In subduction zone the thermal advection play a big role on location of earthquakes.Marshak, 2005
37 How many plates???Seismicity from USGS Volcanoes from Smithsonian institute