  We demonstrate the deterministic generation of multipartite entanglement
based on scalable methods. Four qubits are encoded in $^{40}$Ca$^+$, stored in
a micro-structured segmented Paul trap. These qubits are sequentially entangled
by laser-driven pairwise gate operations. Between these, the qubit register is
dynamically reconfigured via ion shuttling operations, where ion crystals are
separated and merged, and ions are moved in and out of a fixed laser
interaction zone. A sequence consisting of three pairwise entangling gates
yields a four-ion GHZ state $\vert\psi\rangle=\tfrac{1}{\sqrt{2}}\left(\vert
0000\rangle+\vert 1111\rangle\right)$, and full quantum state tomography
reveals a Bell state fidelity of 94.4(3)\%. We analyze the decoherence of this
state and employ dynamic decoupling on the spatially distributed constituents
to maintain 69(5)\% coherence at a storage time of 1.1~seconds.
