Category: Physics

Summary: Estimating when stronger dike-mediated compliance causes the softest elastic mode to span two magma chambers and the connecting dike instead of remaining trapped in one reservoir or the surrounding crust.

Volcanic systems often involve more than one magma reservoir linked by intrusions, yet it remains unclear when that connection is strong enough to make the dominant elastic response genuinely shared across the whole structure. This experiment asks for the threshold where increasing dike-mediated compliance creates a balanced chamber-dike-chamber soft mode rather than leaving deformation localized in one chamber or in the host crust.

The model constructs dense elastic crust operators with two chamber regions, a central dike corridor, and heterogeneous background structure. It then uses iterative deepening with repeated eigensolves to bisect the coupling strength, tracking whether the softest mode places enough weight on both chambers and the dike while remaining separated from the exterior crust.

That makes the result a structural transition map for coupled reservoir mechanics. The emphasis is on identifying the onset of a bridge-localized soft mode in a dense finite-size setting, which goes beyond standard elastic interaction studies that typically do not chart this threshold directly.

Method: Dense symmetric eigensolves with iterative deepening and bisection on dike-coupling strength eta across elastic crust operators from N=64 to 2048.

What is measured: Critical coupling threshold, bracket width, softest eigenvalue, eigenvalue gap ratio, bridge ratio, left and right chamber mass, dike mass, exterior mass, and chamber balance.