https://www.kaelynnrose.com/contact daily 0.75 2021-01-29 https://www.kaelynnrose.com/research daily 0.75 2021-01-25 https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610669398374-R88LFB1PIJE1PJ767VZ2/1449768001.jpg Geophysics Research at UCSB Figure from Alaska Volcano Observatory (https://www.avo.alaska.edu/about/infrasound.php) https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610669369635-UCH0WNRWPLZP68WBAG4C/Evers2010.png Geophysics Research at UCSB Figure from Evers and Haak (2010) showing atmospheric temperature profile with altitude, from the U.S. Standard Atmosphere (NOAA et al., 1976). https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610664516629-ORTIO1KC2WSRJLLMAMB3/Picture1.png Geophysics Research at UCSB Sound travels with high efficiency and low attenuation in the ocean due to the presence of the SOFAR channel. https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610666452478-MMOUV5OXVPKLPCJU0JZP/Jensen2011b.png Geophysics Research at UCSB Figure from Jensen et al. (2011) showing SOFAR channel propagation, where acoustic waves are focused along the SOFAR channel axis with minimal loss at the sea surface or seafloor boundaries. https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610852033899-GDQNHKY00BIH7RED41S5/Screen+Shot+2021-01-16+at+6.53.23+PM.png Geophysics Research at UCSB https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610668339521-4CPSI2H5AS6H1KITK74U/globalims.png Geophysics Research at UCSB Figure from Rose (2020). Station locations of the IMS global infrasound network (white triangles) and global hydroacoustic network (white circles). Hydroacoustic stations are labeled with their station names. Locations of globally potentially active volcanoes are represented by colored triangles, where subaerial or partially submerged volcanoes are shown as red triangles, and submarine volcanoes are shown as blue triangles. It is highly likely that many other active submarine volcanoes exist, but have not yet been identified. Data from Global Volcanism Program, 2013 (GVP, 2013). https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610663059168-H4SYPPRTE9I7P6ZWCG4P/krakatau1883.jpg Geophysics Research at UCSB Krakatau before the 1883 eruption which destroyed its edifice. Source: Getty Images. https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610663363506-77KLRAV8T6D06UCE3D3X/krakatauincandescent.jpg Geophysics Research at UCSB Photo of Anak Krakatau in July 2018, with incandescent material erupting from its summit crater. Source: Getty Images. https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610663139113-L9QY0RC3U24KX5C9O8DT/krakatauaerial.jpg Geophysics Research at UCSB Aerial view of Anak Krakatau and surrounding islands, from August 2018 before the major eruption. Source: Getty Images. https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610665647171-2W3MCL8D6BRS8U5OSVX8/beforeandafter.png Geophysics Research at UCSB Anak Krakatau before and after the major eruption and collapse of the volcanic cone on December 22, 2018. Photos: Øystein Lund Andersen (top) and James Reynolds (bottom) https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610665067086-5C3CTZWBI81UHWZC9WQH/satellite.png Geophysics Research at UCSB Figure from Rose (2020). Sentinel-2 thermal satellite images of Anak Krakatau from just before the start of the new eruptive phase in June 2018 to three months after the flank collapse in March 2019 https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610850897048-IOULCOXL2RJVMADG9W6F/3infra_comparison.png Geophysics Research at UCSB Figure from Rose (2020). Comparison of PMCC bulletin detections at stations IS06, IS07, and IS52. The upper three panels show ±15 degrees from each respective Anak Krakatau back-azimuth (black dashed lines), with a vertical red dashed line indicating the flank collapse event. A large number of detections are present at station IS06, beginning on day 356 (December 22, 2018) and continuing to early January 2019. Station IS07 does not show sustained detections from Anak Krakatau. Station IS52 detected continuous detections near the correct back-azimuth of the volcano for this time frame, though these don’t capture the start of the eruption or flank collapse and are partially obscured by microbarom clutter. Bottom panel: detection cross-bearings for the two infrasound stations where coherent detections were observed. The mean back-azimuth of PMCC detections attributed to Anak Krakatau were calculated for IS06 and IS52, and the great circle paths at those back-azimuths are indicated by solid orange lines. The location of Anak Krakatau is indicated by a red triangle. The back-azimuth intersection location is 124 km from true. Station IS07 is indicated by a gray inverted triangle and no detection path shown due to lack of coherent sustained infrasound from the eruption at this station. https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610671397857-ZOO5F6OXWQPPD915Y1CA/infra_spectrograms.png Geophysics Research at UCSB https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610848602625-VFULL3UISS2GLSGFR8PM/day356infratriggers.png Geophysics Research at UCSB Figure from Rose (2020). Example dayplot of 24 hours of IS06 infrasound waveform data, with PMCC detections identified with pink circles and triggered event start times indicated by blue vertical lines. The climactic eruption occurred from 06:40 to 13:55 (UTC). After this point, the signal amplitude decreases and becomes less consistent. https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610848990600-2MV9L6VR4411C80WRZLH/infraamps_fancy.png Geophysics Research at UCSB Figure from Rose (2020). top panel shows PMCC detections coming from the direction of Anak Krakatau volcano. Middle panel shows the maximum amplitude of each of the 10,324 automatically picked events. Bottom panels show SAR imagery from Sentinel-1 satellite. https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610849181247-GSXE570CGEMFS8CAON3E/Screen+Shot+2021-01-16+at+6.05.40+PM.png Geophysics Research at UCSB https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610849612178-RUCSNR7GAEJ437EQLMIH/I06H_xcormat.png Geophysics Research at UCSB Figure from Rose (2020). Cross-correlation matrix showing cross correlation coefficient values between each pair of picked IS06 infrasound signal events from December 19-29, 2018. During the pre-collapse eruption the events did not have high correlation (i.e. were not repetitive). After the flank collapse, the events are more highly correlated with each other, possibly representing discrete Surtseyan explosions. They are well correlated throughout the remainder of the eruption and do not appear to evolve significantly over time, suggesting the process of their generation is constant. https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610849945973-08F3PL490PWZLT3GK55I/all_multiplets.png Geophysics Research at UCSB Figure from Rose (2020). Multiplet waveforms of station IS06 infrasound signal in temporal order starting at Event 0, aligned by cross-correlation. The upper left panel shows the largest multiplet, Multiplet 1, with 1,709 events, where each row of the matrix shows an event waveform with red colors indicating positive pressure and blue colors indicating negative pressure of the wave. Below the waveform matrix is the mean waveform stack for the multiplet. The lower left panel shows the second-largest multiplet, Multiplet 2, with 839 events, and its corresponding stack. The right panel shows every event that was assigned to a multiplet. The time of the beginning of the climactic phase of the eruption is indicated by a cyan horizontal line. The time of the flank collapse and tsunami is indicated by a yellow horizontal line. https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610850179341-SQ27IUGRW3155MFOZB0G/families_large.png Geophysics Research at UCSB Figure from Rose (2020). The four largest families of events identified at IS06 (infrasound). The first row of panels show individual waveforms of the family in gray, and the master waveform stack of the family as a solid black line. The second row of panels show event matrices for the families in chronological order with the first event at 0. The events are aligned via cross correlation to the best-correlated waveform in the family. The third row of panels show the PSDs for each family. Individual PSDs for each event are shown in gray, the average PSD is shown in turquoise, and the PSD of the waveform master stack is shown in black. The fourth row of panels shows every event as the maximum amplitude of the event vs the time of the event (black dots) and identifies the events assigned to the family (red dots). The master waveforms for each family appear qualitatively similar, but have variable frequency content. https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610850796449-9BP5LJR8I9MW671HO5KF/2panel_hydro.png Geophysics Research at UCSB From Rose (2020). Comparison of PMCC hydroacoustic detections at H08S and H01W and detection cross-bearings. PMCC bulletin detections are present prior to the flank collapse eruption at both stations. The back-azimuth to Anak Krakatau is indicated by a gray dashed line and the time of the flank collapse is indicated by a vertical blue dashed line on each PMCC detections plot. The flank collapse eruption phase was not detected, possibly due to predominantly subaerial eruptive activity. Bottom panel: locations of stations H08 and H01 are indicated by blue circles, and the location of Anak Krakatau is indicated by a red triangle. The mean back-azimuth of PMCC detections attributed to Anak Krakatau was calculated for each station, and the great circle paths pro- jected in the direction of the mean back-azimuths are indicated by solid orange lines. The hydroacoustic swarm signals from the two stations overlap near the location of Anak Krakatau, 119 km from true. https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610852449129-88CVQJVC5DIO7RJLGKFW/max_amplitudes_hydro.png Geophysics Research at UCSB Figure from Rose (2020). Summary of H08S hydroacoustic swarm events from November 29 - December 11, 2018. Top panel: PMCC families detections, with colors representing mean frequency of the detection in log scale. The black dashed line is the back-azimuth of Anak Krakatau, 84.9 degrees. Middle panel: the 2,169 manually picked hydroacoustic events, plotted by maximum amplitude of the signal. During this timeframe, seismic events and ash plumes were recorded on December 1-3 and December 7-9, 2018 (GVP, 2018). The row of panels below show Sentinel satellite imagery, the first panel showing a thermal anomaly in the crater on November 29, 2018 from the Sentinel-2 L1C SWIR band, and the right three panels showing Sentinel-1 SAR GRD satellite imagery (Modified Copernicus Sentinel Data, 2019). https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610852682873-4ADS5FAISYNTWJHQEURU/families_largest4.png Geophysics Research at UCSB Figure from Rose (2020). The four largest families of hydroacoustic events picked from station H08S hydroacoustic data. The first row of panels show individual waveforms of the family in gray, and the master waveform stack of the family in solid blue. The second row of panels show event matrices for the families in temporal order, aligned by cross-correlation to the best-correlated waveform in the family. The third row of panels show the PSDs for each family, with the individual PSDs for each event in gray, the average PSD shown in turquoise, and the PSD of the mean family stack in black. The fourth row of panels shows the plot of all events, where events are plotted by their maximum amplitude vs. time, and identifies events assigned to the family in red. https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1611544391799-G5VAT4USRCYA6DSJPYH2/summary.png Geophysics Research at UCSB https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1605910997675-IYZH43DKXWQB6K85ITTF/picture_4_-_anak_k.png Geophysics Research at UCSB https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1610851303755-ACUZ32T71AVORWCYQT8T/volcanohazards.png Geophysics Research at UCSB Geophysical techniques such as infrasound and hydroacoustic signal analysis have the potential to detect eruptions in remote areas or in the ocean where they might otherwise go unnoticed. These methods are finding increasing utility for volcanic hazard mitigation, as submarine or partially submerged volcanoes pose numerous threats, including: Ash plumes and tephra fall Explosions and ballistics Pyroclastic flows and base surges Lahars and flooding Mass wasting events such as landslides and flank collapses Tsunamis https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1605910719812-QDD6ZCJQY4JO9ME7HQP2/Mt.Mayon_tam3rd.jpg Geophysics Research at UCSB https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1605911015091-UQZ8PUKI371CU3NQKE3M/eight_col_LeHavreNiwa.jpeg Geophysics Research at UCSB https://www.kaelynnrose.com/about daily 1.0 2024-11-13 https://images.squarespace-cdn.com/content/v1/5fa1da75cbd38d26461e4df4/1611945048523-ACZRHDHHOM6J0SB1MDYB/studiolight2.jpeg About