This paper extends and detides a Karachi tide-gauge record as an observational basis for assessing Indian Ocean tsunami risk. The extended marigram encompasses the time of the great 1945 Makran earthquake of early November 28, local time, and of the ensuing tsunami, which continued into November 29. The marigram was published previously as a 9-h excerpt that begins 1 h after the earthquake. The full marigram presented here covers most of 17 days from November 15 to December 1. Gaps include a tsunami-induced outage that may help explain why the highest water level gauged is 1 m below the maximum water level reported nearby. The detiding method computes a reference tidal curve that disregards all observations from November 28 and 29. For those 2 days, the reference tide is guided by Admiralty tide tables and, secondarily, by high waters and low waters gauged before and after. As in previous estimates, the detided tsunami crests about 0.5 m above ambient tide, but now with the possibility that the gauge failed to record a higher wave. Anomalies described for the first time include an early one that likely resulted from a recognized problem with the Karachi tide station, but which might instead represent an earthquake precursor.

中文翻译：

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1945年马克兰海啸期间的卡拉奇潮

本文扩展并确定了卡拉奇潮汐计记录，作为评估印度洋海啸风险的观察基础。扩展的marigram包含当地时间11月28日1945年马克兰大地震以及随后的海啸的持续时间，海啸一直持续到11月29日。marigram以前作为9小时摘录发布，从地震后1 h开始。从11月15日到12月1日的17天中，大部分时间段都显示完整的航海图。缺口包括海啸引起的停运，这可能有助于解释为什么测得的最高水位比附近报告的最高水位低1 m。确定方法计算的基准潮汐曲线忽略了11月28日和29日的所有观测值。在这两天中，基准潮汐由金钟潮汐表指导，其次，之前和之后的高水位和低水位。如先前的估计那样，已退役的海啸波峰比周围的潮汐高约0.5 m，但现在有可能该仪表未能记录到更高的波浪。第一次描述的异常包括一个早期的异常，它可能是由于卡拉奇潮汐站的一个公认的问题导致的，但可能代表了地震的先兆。