  The angular momentum of gas feeding a black hole (BH) is typically misaligned
with respect to the BH spin, resulting in a tilted accretion disk. Rotation of
the BH drags the surrounding space-time, manifesting as Lense-Thirring torques
that lead to disk precession and warping. We study these processes by
simulating a thin ($H/r=0.02$), highly tilted ($\mathcal{T}=65^\circ$)
accretion disk around a rapidly rotating ($a=0.9375$) BH at extremely high
resolutions, which we performed using the general-relativistic
magnetohydrodynamic (GRMHD) code H-AMR. The disk becomes significantly warped
and continuously tears into two individually precessing sub-disks. We find that
mass accretion rates far exceed the standard $\alpha$-viscosity expectations.
We identify two novel dissipation mechanisms specific to warped disks that are
the main drivers of accretion, distinct from the local turbulent stresses that
are usually thought to drive accretion. In particular, we identify extreme
scale height oscillations that occur twice an orbit throughout our disk. When
the scale height compresses, `nozzle' shocks form, dissipating orbital energy
and driving accretion. Separate from this phenomenon, there is also extreme
dissipation at the location of the tear. This leads to the formation of
low-angular momentum `streamers' that rain down onto the inner sub-disk,
shocking it. The addition of low angular momentum gas to the inner sub-disk
causes it to rapidly accrete, even when it is transiently aligned with the BH
spin and thus unwarped. These mechanisms, if general, significantly modify the
standard accretion paradigm. Additionally, they may drive structural changes on
much shorter timescales than expected in $\alpha$-disks, potentially explaining
some of the extreme variability observed in active galactic nuclei.
