Correct handling of strong elastic internal multiples remains a challenge for seismic imaging. Methods aimed at eliminating them are currently limited by monotonicity violations, a lack of a-priori knowledge about mode conversions, or unavailability of multicomponent sources and receivers for not only particle velocities but also the traction vector. Most of these challenges vanish in acoustic media such that Marchenko-equation-based methods are able, in theory, to remove multiples exactly (within a certain wavenumber-frequency band). In practice, however, when applied to (elastic) field data, mode conversions are unaccounted for. Aiming to support a recently published marine field data study, we build a representative synthetic model. For this setting, we demonstrate that mode conversions can have a substantial impact on the recovered multiple-free reflection response. Nevertheless, the images are significantly improved by acoustic multiple elimination. Moreover, after migration the imprint of elastic effects is considerably weaker and unlikely to alter the seismic interpretation.

中文翻译：

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内部多重消除：我们可以相信声学近似吗？

正确处理强弹性内部多次波仍然是地震成像的挑战。旨在消除它们的方法目前受到单调性违反、缺乏关于模式转换的先验知识或多分量源和接收器不可用的限制，不仅包括粒子速度，还包括牵引矢量。大多数这些挑战在声学介质中都消失了，因此基于 Marchenko 方程的方法在理论上能够准确地去除倍数（在某个波数 - 频带内）。然而，实际上，当应用于（弹性）场数据时，模式转换是下落不明的。为了支持最近发表的海洋野外数据研究，我们构建了一个具有代表性的合成模型。对于此设置，我们证明了模式转换可以对恢复的多次自由反射响应产生重大影响。尽管如此，通过声学多重消除显着改善了图像。此外，迁移后弹性效应的印记相当弱，不太可能改变地震解释。