Well maybe you'll listen to USGS for some answers to your questions TomK. The "blips" or "diurnal noise" are real readings from the instrument caused by the thermal expansion of the surrounding rock.
https://www.usgs.gov/observatories/hvo/n...nsequences
"One non-volcanic source of tilt is the heating of the ground that happens on sunny days. Most of HVO’s tiltmeters are installed in boreholes about 3 to 4 m (10 to 13 ft) below the ground and are surrounded by rock. This rock expands as it warms up during the day, and any unevenness in its expansion will produce an easily measurable ground tilt. This is “diurnal noise,” which can be easily identified because it happens regularly during the day."
This uneven expansion partially helps answer my question as to why the daily tilt pattern happens at all, but not why it appears to always be in an inflationary direction in the data provided. My guess is that each tilt meter would have a particular diurnal noise pattern that is consistent with the thermal expansion of the surrounding rock, but for some meters that might cause a downward dip or other effect seen daily in the data. The inflationary pattern just happens to be the daily pattern for the tilt meter providing the data under discussion. Would that make sense MyManao? Are there other tilt meters showing other distinct diurnal noise patterns?
As for the effects the diurnal pattern may have on eruptions, that's beyond my paygrade, but I did run across this interesting paper about tilt meters at Mt Etna, and how even over a decade ago they have reached the sensitivity where they can detect Earth Tide effects, or the movement of the ground due to the passing gravitational pull of the moon and sun (midday surge?), and some speculation that apparently dates to at least the 1930s that such earth tide effects may have some influence on earthquakes and volcanic eruptive activities. All of which is wild to me.
If the diurnal warming has at least as much effect as the earth tide on tilt (which it appears to based on the numbers?) then speculation about its possible effects on eruptive activity seems reasonable to consider?
I highly doubt anyone is checking scientific credentials at the PunaWeb door, nor is anyone saying they should - only noting that everyone should assume the best, ask questions, and be open to answers and discussion? As those old Zen Buddhists like to note, "In the beginner's mind there are many possibilities, but in the expert's there are few."
https://www.usgs.gov/observatories/hvo/n...nsequences
"One non-volcanic source of tilt is the heating of the ground that happens on sunny days. Most of HVO’s tiltmeters are installed in boreholes about 3 to 4 m (10 to 13 ft) below the ground and are surrounded by rock. This rock expands as it warms up during the day, and any unevenness in its expansion will produce an easily measurable ground tilt. This is “diurnal noise,” which can be easily identified because it happens regularly during the day."
This uneven expansion partially helps answer my question as to why the daily tilt pattern happens at all, but not why it appears to always be in an inflationary direction in the data provided. My guess is that each tilt meter would have a particular diurnal noise pattern that is consistent with the thermal expansion of the surrounding rock, but for some meters that might cause a downward dip or other effect seen daily in the data. The inflationary pattern just happens to be the daily pattern for the tilt meter providing the data under discussion. Would that make sense MyManao? Are there other tilt meters showing other distinct diurnal noise patterns?
As for the effects the diurnal pattern may have on eruptions, that's beyond my paygrade, but I did run across this interesting paper about tilt meters at Mt Etna, and how even over a decade ago they have reached the sensitivity where they can detect Earth Tide effects, or the movement of the ground due to the passing gravitational pull of the moon and sun (midday surge?), and some speculation that apparently dates to at least the 1930s that such earth tide effects may have some influence on earthquakes and volcanic eruptive activities. All of which is wild to me.
If the diurnal warming has at least as much effect as the earth tide on tilt (which it appears to based on the numbers?) then speculation about its possible effects on eruptive activity seems reasonable to consider?
I highly doubt anyone is checking scientific credentials at the PunaWeb door, nor is anyone saying they should - only noting that everyone should assume the best, ask questions, and be open to answers and discussion? As those old Zen Buddhists like to note, "In the beginner's mind there are many possibilities, but in the expert's there are few."