This study mainly deals with the consequences of inadequate data coverage on the interpretation of geophysical information. The results of the joint gravity and geomagnetic survey of the Ciomadul Volcano are discussed in connection with conclusions of previously performed magneto-telluric (MT) investigations.In the first step, inversion of both the potential fields and MT data apparently suggested the existence of a shallow (i.e., <5 km) magma chamber containing residual melt, or alternatively, highly hydrothermally altered rocks. However, strong arguments exist against both of these hypotheses such as lack of strong geothermal manifestations at the surface, or the too young age of the volcano, inconsistent with the assumed advanced alteration stage.

During the next step, a brief study on the limitations of the inversion approach revealed significant shortcomings generated by uneven data distribution. Based on these conclusions, the gravity inversion results were reconsidered by substituting the initially assumed single magma chamber with a hypothetical swarm of narrow volcano conduits, each with size below the Nyquist threshold of the gravity survey as determined by an observations coverage density of less than one station/km².

The new 3D density-based model was obtained by forward modelling, unveiling the structure of the shallow part of the volcanic feeder system that gradually developed and branched bottom-to-top.Given the shortcomings of the inversion due to inappropriate data coverage, it was speculated that a former solution of MT inversion might have been biased also by data scarcity. That leads to the integration of local effects (caused by narrow, but highly conductive fluid-filled conduits) into a single electrical resistivity anomaly that is improperly interpreted.

本研究主要处理数据覆盖不足对地球物理信息解释的影响。结合先前进行的大地电磁 (MT) 调查的结论讨论了 Ciomadul 火山的联合重力和地磁调查的结果。第一步，势场和 MT 数据的反演显然表明存在一个含有残余熔体或高度热液蚀变岩石的浅层（即<5 公里）岩浆房。然而，对于这两种假设都存在强有力的论据，例如地表缺乏强烈的地热表现，或者火山的年龄太小，与假设的晚期蚀变阶段不一致。

在下一步中，对反演方法局限性的简要研究揭示了不均匀数据分布所产生的重大缺陷。基于这些结论，重新考虑重力反演结果，将最初假设的单个岩浆房替换为假设的一群狭窄的火山通道，每个通道的大小都低于重力测量的奈奎斯特阈值，由观测覆盖密度小于 1站/公里² .

新的基于 3D 密度的模型是通过正演建模获得的，揭示了火山馈给系统的浅部逐渐发育和自下而上分支的结构。推测以前的 MT 反演解决方案也可能因数据稀缺而存在偏差。这导致将局部效应（由狭窄但高度导电的充满流体的管道引起）整合到一个被错误解释的单一电阻率异常中。