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Realtime data from BOTPT-A304-MJ03B - ASHES Vent Field


This page displays plots of near-real-time data (updated every 15 minutes) from one of four BPR/Tilt (BOTPT) instruments at Axial Seamount, part of the National Science Foundation's (NSF) Ocean Observatories Initiative (OOI) Cabled Array seafloor observatory, operated by the University of Washington. The BOTPT instruments were built by NOAA's Pacific Marine Environmental Lab (PMEL) and Oregon State University (OSU). The BPR/Tilt instruments have 4 sensors: 1) a nano-resolution bottom pressure recorder (NANO), 2) a high-resolution tiltmeter (LILY), 3) a low-resolution tiltmeter (IRIS) , and 4) a coarse-resolution tiltmeter (HEAT). The dates/times in the plots below are in GMT (+8 hrs of local PST, or +7 hrs of PDT time on the US west coast). NOTE: THIS INSTRUMENT WAS DEPLOYED AND THEN POWERED UP ON AUGUST 15, 2017 (~3 years later than the other 3 instruments).

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Bottom Pressure Recorder (NANO-BPR)

The NANO-BPR precisely measures the pressure of the overlying ocean. The raw BPR pressure data are converted to depth (blue) and include the ocean tides. After subtracting predicted tides, the difference (red) shows vertical movements of the seafloor and other residual signals. Temperature data are shown in green. Separate plots below show (1) the last 3 days of pressure data and (2) the entire OOI time-series, with and without tides. We are using predicted tides generated by Rick Thomson at the Institute of Ocean Sciences in Sydney, BC, based on the OOI BPR data from Axial. The short-term apparent depth variations of ±5-15 cm over hours to days do NOT appear to be geophysical in origin, and instead reflect some combination of varying atmospheric pressure, oceanographic conditions, and misfit with predicted tides. This interpretation is supported by the fact that the tiltmeter data (below) do not show these short-term variations. However, the longer-term depth changes over weeks-months-years DO reflect volcanic inflation/deflation and the magmatic cycle at the volcano.

Plot of de-tided BPR data

Plot 1: NANO-BPR pressure data with predicted tides removed (red) and temperature (green), over the last 3 days.

 

Plot of de-tided BPR data

Plot 2: NANO-BPR pressure data with predicted tides removed (red) and temperature (green), over the entire record. The blue line is the de-tided pressure data smoothed over a 4-day time window to minimize the tidal residuals. ONLY UPDATED ONCE PER DAY.

 

Plot of BPR data

Plot 3: NANO-BPR pressure data showing equivalent seafloor height (in meters), with and without tides, over the last 3 days.

 

Plot of BPR data

Plot 4: NANO-BPR pressure data showing equivalent seafloor height (in meters), with and without tides, over the entire record. ONLY UPDATED ONCE PER DAY.


High-resolution tiltmeter (LILY)

The plots below are from the high-resolution tiltmeter (LILY), with tilt data measured on two perpendicular axes in microradians, which is a precise angular measure in parts per million. For example, one microradian is the amount a 1-km-long bar would be tilted, if one end were lifted up by 1 mm. The resultant tilt magnitude and direction (using the sensor's compass data) are also shown. Abrupt vertical lines are ground motion recorded during earthquakes. The LILY tiltmeter can be automatically re-leveled when it gets close to being out of range (+/- 330 microradians). Large tilt off-sets in the record are when the instrument was re-leveled.

PPlot of LILY X and Y tilt

Plot 5: LILY X-axis tilt (blue) and Y-axis tilt (pink), in microradians, and temperature (green), over the last 3 days.

 

Plot of LILY X and Y tilt

Plot 6: LILY X-axis tilt (blue) and Y-axis tilt (pink), in microradians, and temperature (green), over the entire record. ONLY UPDATED ONCE PER DAY.


The set of 2 plots below show the resultant tilt magnitude (red) and direction (purple) calculated from the raw X- and Y-tilts (recorded once a second), so these effectively show the resultant tilt since the last LILY re-leveling.

 

Plot of LILY tilt magnitude and direciton

Plot 7: Resultant tilt magnitude (red) and direction (purple) over the last 3 days.

 

Plot of LILY tilt magnitude and direciton

Plot 8: Resultant tilt magnitude (red) and direction (purple) over the entire record. ONLY UPDATED ONCE PER DAY.


The 2 plots below show the resultant tilt magnitude (red) and direction (purple), calculated from hourly averages of the the X- and Y-tilts relative to the values 1 week earlier, so these effectively show the weekly rate of tilt and how it has changed with time. These plots are only updated once per day.

 

Plot of LILY tilt magnitude and direciton

Plot 9: Resultant tilt magnitude (red) and direction (purple) over the last 7 days - RELATIVE TO 1 WEEK EARLIER.

 

Plot of LILY tilt magnitude and direciton

Plot 10: Resultant tilt magnitude (red) and direction (purple) over the entire record - RELATIVE TO 1 WEEK EARLIER.


Low-resolution tiltmeter (IRIS)

A low-resolution tiltmeter is needed to put the high-resolution tilt measurements into context. This instrument measures the tilt less precisely than the LILY tiltmeter, but it has a much larger dynamic range. Below are two plots of X- and Y-tilt without temperature (one over the last 3 days, and one over the entire record), and below that two plots with temperature.

 

Plot of low-resolution tilt data

Plot 11: X-axis (left, blue) and Y-axis (right, pink) low-resolution IRIS tilts (in degrees), over the last 3 days.

Plot of low-resolution tilt data

Plot 12: X-axis (left, blue) and Y-axis (right, pink) low-resolution IRIS tilt (in degrees), over the entire record. ONLY UPDATED ONCE PER DAY.

Plot of low-resolution tilt data

Plot 13: X-axis and Y-axis low-resolution IRIS tilt (in degrees) and temperature (C), over the last 3 days.


Plot of low-resolution tilt data

Plot 14: X-axis and Y-axis low-resolution IRIS tilt (in degrees) and temperature (C), over the entire record. ONLY UPDATED ONCE PER DAY.


Coarse-resolution tiltmeter (HEAT)

A coarse-resolution tiltmeter is needed to put the high-resolution tilt measurements into context. This instrument measures the tilt to the nearest degree (a million times less precise than the LILY tiltmeter), but it has a much larger dynamic range, so it shows us the gross orientation of the instrument on the seafloor. The data from this low-resolution tiltmeter are not expected to change with time, but we plot them here anyway.

 

Plot of low-resolution tilt data

 

Plot 15: X-axis and Y-axis low-resolution tilt (in degrees) and temperature (C), over the last 3 days.

 

Plot of low-resolution tilt data

Plot 16: X-axis and Y-axis low-resolution tilt (in degrees) and temperature (C), over the entire record. ONLY UPDATED ONCE PER DAY.


More information

National Science Foundation | The Ocean Observatories Initiative | Cabled Array Observatory

 

Required OOI disclaimer: This is provided as pre-commissioned data intended for scientific use, and is subject to the OOI Data Policy. This data has not been through Quality Assurance checks.

 

Required NSF disclaimer: This material is based upon work supported by the National Science Foundation. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.