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Rivers and turbidity currents are the two most important sediment transport processes by volume on Earth. Various hypotheses have been proposed for triggering of turbidity currents offshore from river mouths, including direct plunging of river discharge, delta mouth bar flushing or slope failure caused by low tides and gas expansion, earthquakes and rapid sedimentation. During 2011, 106 turbidity currents were monitored at Squamish Delta, British Columbia. This enables statistical analysis of timing, frequency and triggers. The largest peaks in river discharge did not create hyperpycnal flows. Instead, delayed delta-lip failures occurred 8–11 h after flood peaks, due to cumulative delta top sedimentation and tidally-induced pore pressure changes. Elevated river discharge is thus a significant control on the timing and rate of turbidity currents but not directly due to plunging river water. Elevated river discharge and focusing of river discharge at low tides cause increased sediment transport across the delta-lip, which is the most significant of all controls on flow timing in this setting.

The study of ionospheric disturbances associated with the two large strike-slip earthquakes in Indonesia was investigated, which are West Sumatra on 2 March 2016 (Mw = 7.8), and Palu on 28 September 2018 (Mw = 7.5). The anomalies were observed by measuring co-seismic ionospheric disturbances (CIDs) using the Global Navigation Satellite System (GNSS). The results show positive and negative CIDs polarization changes for the 2016 West Sumatra earthquake, depending on the position of the satellite line-of-sight, while the 2018 Palu earthquake shows negative changes only due to differences in co-seismic vertical crustal displacement. The 2016 West Sumatra earthquake caused uplift and subsidence, while the 2018 Palu earthquake was dominated by subsidence. TEC anomalies occurred about 10 to 15 min after the two earthquakes with amplitude of 2.9 TECU and 0.4 TECU, respectively. The TEC anomaly amplitude was also affected by the magnitude of the earthquake moment. The disturbance signal propagated with a velocity of ~1–1.72 km s−1 for the 2016 West Sumatra earthquake and ~0.97–1.08 km s−1 for the 2018 Palu mainshock earthquake, which are consistent with acoustic waves. The wave also caused an oscillation signal of ∼4 mHz, and their azimuthal asymmetry of propagation confirmed the phenomena in the Southern Hemisphere. The CID signal could be identified at a distance of around 400–1500 km from the epicenter in the southwestern direction.

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Pantai selatan Jawa merupakan daerah pesisir yang berbatasan langsung dengan Samudera Hindia. Batas inilah yang secara langsung mempengaruhi karakteristik oseanografi di daerah pantai Selatan Jawa. Fenomena sedimentasi dari tahun ke tahun juga semakin besar, hal ini dibuktikan dengan berubahnya garis pantai di selatan Jawa, banyak pantai yang mengalami abrasi dan banyak juga yang mengalami akresi. Penelitian ini bertujuan untuk mengetahui dampak dari proses abrasi dan sedimentasi di daerah pantai selatan Jawa berdasarkan pola sebaran arus yang terdapat di daerah penelitian. Model hidrodinamika digunakan untuk melakukan simulasi pola sebaran arus dan sebaran sedimen. Simulasi ini dilakukan pada dua bulan yaitu bulan Maret (mewakili curah hujan tertinggi) dan bulan Oktober (mewakili curah hujan terendah). Dari hasil simulasi di area penelitian, pola arus yang terjadi di wilayah tersebut memiliki nilai kurang dari 6,921 m/s pada bulan Maret dan 7,60 m/s pada bulan Oktober. Besar konsentrasi sedimen tertinggi yang terjadi di sepanjang lokasi penelitian yaitu pada bulan Maret sebesar 8972,23 g/m3 dan pada bulan Oktober sebesar 4247,26 g/m3.